Cardiac analysis user interface system and method

ABSTRACT

Methods of generating a graphical representation of cardiac information on a display screen are provided. The method comprises: electronically creating or acquiring an anatomical model of the heart including multiple cardiac locations; electronically determining a data set of source information corresponding to cardiac activity at the multiple cardiac locations; electronically rendering the data set of source information in relation to the multiple cardiac locations on the display screen. Systems and devices for providing a graphical representation of cardiac information are also provided.

CROSS REFERENCES TO RELATED APPLICATIONS

The present application claims priority under 35 USC 119(e) to U.S.Provisional Application Ser. No. 61/970,027, entitled CARDIAC ANALYSISUSER INTERFACE SYSTEM AND METHOD, filed Mar. 25, 2014, which isincorporated herein by reference in its entirety.

The present application, while not claiming priority to, may be relatedto Applicant's co-pending U.S. Design patent application No. 29/475,273,entitled Transducer-Electrode Arrangement, filed Dec. 2, 2013, theentirety of which is incorporated herein by reference.

The present application, while not claiming priority to, may be relatedto Applicant's co-pending U.S. patent application Ser. No. 14/422,941,entitled Catheter System and Methods of Medical Uses of Same, IncludingDiagnostic and Treatment Uses for the Heart, filed Feb. 5, 2015, andInternational Application No. PCT/US2013/057579, entitled CatheterSystem and Methods of Medical Uses of Same, Including Diagnostic andTreatment Uses for the Heart, filed Aug. 30, 2013, which claimedpriority to U.S. Provisional Patent Application No. 61/695,535, entitledSystem and Method for Diagnosing and Treating Heart Tissue, filed Aug.31, 2012, each of which is hereby incorporated by reference.

The present application, while not claiming priority to, may be relatedto Applicant's co-pending U.S. patent application Ser. No. 14/003,671,entitled Device and Method For the Geometric Determination of ElectricalDipole Densities on the Cardiac Wall, filed Mar. 9, 2012, andInternational Application No. PCT/US2012/028593, entitled Device andMethod for the Geometric Determination of Electrical Dipole Densities onthe Cardiac Wall, filed Mar. 9, 2012, which claimed priority to U.S.Provisional Patent Application No. 61/451,357, entitled Device andMethod for the Geometric Determination of Electrical Dipole Densities onthe Cardiac Wall, filed Mar. 10, 2011, each of which is herebyincorporated by reference.

The present application, while not claiming priority to, may be relatedto U.S. patent application Ser. No. 13/946,712, entitled A Device andMethod for the Geometric Determination of Electrical Dipole Densities onthe Cardiac Wall, filed Jul. 19, 2013, which is a continuation of U.S.Pat. No. 8,512,255, entitled A Device and Method for the GeometricDetermination of Electrical Dipole Densities on the Cardiac Wall, filedJul. 16, 2010, published as US20100298690, which was a 35 USC 371 anational stage application of Patent Cooperation Treaty Application No.PCT/IB09/00071 filed Jan. 16, 2009, entitled A Device and Method for theGeometric Determination of Electrical Dipole Densities on the CardiacWall, published as WO 2009/090547, which claimed priority to SwissPatent Application 00068/08 filed Jan. 17, 2008, each of which is herebyincorporated by reference.

The present application, while not claiming priority to, may be relatedto U.S. patent application Ser. No. 14/547,258, entitled Method andDevice for Determining and Presenting Surface Charge and DipoleDensities on Cardiac Walls, filed Nov. 14, 2014, which is a continuationof U.S. patent application Ser. No. 13/858,715, entitled Method andDevice for Determining and Presenting Surface Charge and DipoleDensities on Cardiac Walls, filed Apr. 8, 2013, which is a continuationof U.S. Pat. No. 8,417,313, entitled Method and Device for Determiningand Presenting Surface Charge and Dipole Densities on Cardiac Walls,filed Feb. 3, 2009, published as US2009264781, which was a 35 USC 371national stage filing of PCT Application No. CH2007/000380, entitledMethod and Device for Determining and Presenting Surface Charge andDipole Densities on Cardiac Walls, filed Aug. 3, 2007, published as WO2008/014629, which claimed priority to Swiss Patent Application No.1251/06 filed Aug. 3, 2006, each of which is hereby incorporated byreference.

FIELD OF INTEREST

The invention relates to the field of systems and methods for analyzingcardiac activity and for diagnosing and treating cardiac relatedabnormalities, and in particular to systems and methods that displaycardiac-related information useful in such activities.

BACKGROUND

For identifying the origin(s) of cardiac arrhythmias it is commonpractice to measure the electric potentials located on the inner surfaceof the heart with electroanatomic mapping systems. For example, for thispurpose electrode catheters can be inserted into the heart and movedaround while recording cardiac potentials during normal heart rhythm orcardiac arrhythmia. If the arrhythmia has a regular activation sequence,the timing of local activation measured from the cardiac potentials ateach site visited by the electrode can be combined across many sites andover many heart beats during the arrhythmia, to create a threedimensional “Local Activation Time” (LAT) map of the electricactivation. By doing this, information on the location of the source ofarrhythmia(s) and mechanisms, i.e., foci and reentry circuits, can bediagnosed to initiate or guide treatment (e.g., radiofrequencyablation).

This mapping procedure is often aided by computer systems generatingthree dimensional maps of catheter positions by localizing the catheterwith the help of magnetic fields (the so called Carto System) ortransthoracic impedances (by Localisa and NavX). Because all the pointsof such maps are obtained by electrode positions in contact with thecardiac surface, this mapping system is called “conventional contactmapping”. It has the inherent limitation that cardiac activation canonly be assessed simultaneously at the points in contact with themyocardium. Hence, an instantaneous map of the entire cardiac activationis impossible because the entire heart chamber cannot be contactedsimultaneously without compromising blood circulation. Instantaneousmapping of the entire electric activation of the heart chamber, however,might be advantageous in unstable arrhythmias of short duration, forwhich the conventional mapping procedures (moving the electrode aroundduring the arrhythmia) are too time-consuming compared to this shortduration and are therefore unable to capture a clinically relevantelectric activation map. In addition, an instantaneous map of cardiacelectric activation might be advantageous during irregular arrhythmiasor arrhythmias with non-constant activation sequences that renderaccumulation of activation times from contact mapping impossible.Finally, instantaneous maps of cardiac activation are probably alsofaster and easier obtained, than a contact map generated by timeconsuming catheter movements to different areas of the heart in allsorts of cardiac arrhythmias.

The disadvantage of contact mapping can be overcome by “non-contactmapping,” which allows for mapping cardiac activation of a heart chambersimultaneously without contact to the cardiac wall. For this purpose,for instance, a multi electrode array mounted on an inflatable ballooncan be inserted into the heart. The geometry of the heart chamber isobtained either (i) by reconstruction of a contact map, which isobtained from an accumulation of 3D surface positions during movementswith an electrode catheter within the heart chamber, or (ii) byimporting imaging data from computed tomography or MRI (magneticresonance imaging).

Once the geometry of the cardiac chamber is outlined in a map theinformation of a simultaneous recording of cardiac far field potentials(unipoles) by the multi electrode array can be extrapolated to thedesired cardiac map using advanced mathematical methods. Thisnon-contact mapping has the advantage that it provides the entireelectric activation measured by far field unipolar potentials either insinus rhythm or during arrhythmia without the need for moving anelectrode catheter around the cardiac chamber. This information allowsfor a single beat analysis of cardiac activation and, therefore,unstable, irregular or multifocal arrhythmias can be tracked andtreated. However, the disadvantage of non-contact mapping is that itrelies on far field potentials, which do not allow for the sameprecision in localization as contact mapping (i.e. measuring localelectrograms (potentials) of cardiac activation by touching theendocardium at the site of interest with a mapping electrode).

Furthermore, non-contact mapping is more prone to artifact generationand interference from potentials generated by cardiac re-polarizationand adjacent heart chambers (atria/ventricles). These drawbacks can beovercome to a certain extent with several filtering techniques. However,in many cases these drawbacks also render the localization of cardiacarrhythmias a time-consuming and frustrating intervention.

Therefore, the advantages of non-contact mapping, i.e. the instantaneouscardiac activation maps, have to be balanced against the disadvantages,i.e. the decreased spatial resolution due to recording of far fieldsignals, filtering of artifacts, etc.

Another method for the non-invasive localization of cardiac arrhythmiasis body surface mapping. In this technique multiple electrodes areattached to the entire surface of the thorax and the information of thecardiac electrical activation is simultaneously measured from the bodysurface potentials, called the electrocardiogram (ECG), which areassimilated omtp LAT maps. Complex mathematical methods are required inorder to determine the local time of electric activation in a heartmodel, for instance, one obtained from CT or MRI imaging givinginformation on cardiac size and orientation within the thoracic cavity.

The disadvantage of both mapping methods, i.e. contact and non-contacttypes, is the representation of the electric activity of the heart bymeans of potentials, which are the result of a summation of ioniccharge-sources within the membrane of all cardiac cells spanning theentire 3D volume of the cardiac tissue. This summation of electricforces generated by the ionic charge-sources in cardiac cells providesfor the potentials that are measured by current mapping systems.

Research has indicated that the use of the surface charge densities(i.e. their distribution) or dipole densities (i.e. their distribution)to generate a distribution map (or maps), if successfully, practicably,and reliably determined, can lead to more detailed and preciseinformation on electric ionic activity of local cardiac cells than theconventional determination made using potentials (or voltages). Surfacecharge density or dipole densities represent a precise and sharp set ofinformation of the electric activity with good spatial resolution,whereas potentials resulting from a summation of charge densitiesprovide only a diffuse picture of electric activity. The electric natureof cardiac cell membranes comprising ionic charges of proteins andsoluble ions can be precisely described by surface charge and dipoledensities, but not by conventional measures of potential. The surfacecharge densities and/or dipole densities cannot be directly measured inthe heart, but instead must be mathematically and accurately calculatedstarting from measured potentials. In other words, the information ofvoltage maps obtained by conventional mapping systems can be greatlyrefined when calculating surface charge densities or dipole densitiesfrom these. However, determining surface and dipole densities fromvoltage information and maps is not a trivial mathematical exercise.U.S. Pat. Nos. 8,417,313 B2 and 8,512,255 B2, each to Scharf et al.,describe approach for determining surface and dipole densities fromvoltage information and maps.

Surface charge density means surface charge (Coulombs) per unit area(cm²). A dipole, as such, is a neutral element, wherein one partcomprises a positive charge and the other part comprises the same, butnegative charge. A dipole or surface charge map could be considered torepresent the electric nature of cellular membranes better than voltagemaps, because in a biological environment, ion charges are notmacroscopically separated.

Currently, mapping systems display cardiac images and activity based onmeasured potentials, not dipole or surface charge densities. Asdiscussed above, this inherently includes inaccuracies, since voltagesare averaged and/or smoothed field data and dipole or surface chargedensities are much more accurate source data. Additionally, such displaysystems do not provide a real-time or near real-time display of theheart or cardiac activity because the volume of rapidly changingcardiac-generated voltage data tends to be far too large for real-timeor near real-time mapping using such systems. In fact, such mapping anddisplay systems represent an image of the heart that is not accurate,such as due to left atrial enlargement that can occur during mapping andtreatment procedures. A displayed image of the heart cannot be rapidlyand accurately updated using current systems, so the practitioner mustwork with the inaccurate cardiac image. This is particularlytroublesome, for example, when the practitioner is attempting toprecisely locate heart tissue for ablation—which requires some amount ofguesswork by the practitioner using conventional imaging and displaysystems.

SUMMARY

Methods of generating a graphical representation of cardiac informationon a display screen are provided. The method comprises: electronicallycreating or acquiring an anatomical model of the heart includingmultiple cardiac locations; electronically determining a data set ofsource information corresponding to cardiac activity at the multiplecardiac locations; electronically rendering the data set of sourceinformation in relation to the multiple cardiac locations on the displayscreen. Systems and devices for providing a graphical representation ofcardiac information are also provided.

In accordance with one aspect of the present disclosure, provided is amethod of generating a graphical representation of cardiac informationon a display screen. The method comprises: electronically creating ananatomical model of the heart including multiple cardiac locations;electronically determining a data set of source informationcorresponding to cardiac activity at the multiple cardiac locations; andelectronically rendering the data set of source information in relationto the multiple cardiac locations on the display screen.

In various embodiments, the source information can be data representing,at a location in 3D space, a physical property or properties discrete tothe specific location in 3D space.

In various embodiments, the source information can comprise recordingsignals from at least one sensor.

In various embodiments, the at least one sensor can comprise multiplesensors.

In various embodiments, the multiple sensors can be mounted to anexpandable array constructed and arranged for placement within a cardiacchamber.

In various embodiments, the at least one sensor can comprise: electrode;pH sensor; temperature sensor; or combinations of two or more thereof.

In various embodiments, the source information can comprise: dipoledensity information; surface charge density information; pH information;temperature information; or combinations of two or more thereof.

In various embodiments, electronically determining a data set of sourceinformation can comprise electronically determining multiple sequentialdata sets of source information representing different phases of atleast one cardiac cycle.

In various embodiments, the at least one cardiac cycle can comprisemultiple cardiac cycles.

In various embodiments, the multiple sequential data sets can representdynamic data sets that are updated at least thirty times per second.

In various embodiments, the multiple sequential data sets can representor include dynamic data sets that are updated at least once per second.

In various embodiments, the multiple sequential data sets can representor include dynamic data sets that are updated at least once every 30minutes.

In various embodiments, the source information can be presented in theform of or using a differentiating map.

In various embodiments, the differentiating map can comprise a colormap.

In various embodiments, the differentiating map can comprise a map ofvalue differentiating parameters including: color; contrast; brightness;hue; saturation level; or combinations of two or more thereof.

In various embodiments, the method can comprise electronically renderingthe anatomical model of the heart on the display screen.

In various embodiments, the anatomical model can be created usingsignals from at least one ultrasound transducer.

In various embodiments, the method can comprise displaying a staticimage of the heart on the display screen.

In various embodiments, the static image can comprise an image of theheart temporally proximate the end of systole.

In various embodiments, the static image can comprise an image of theheart temporally proximate the end of diastole.

In various embodiments, the static image of the heart can be updated atleast once every thirty minutes.

In various embodiments, the method can comprise displaying a dynamicimage of the heart comprising multiple images of a cardiac cycle on thedisplay screen.

In various embodiments, the method can comprise displaying a dynamicimage of the heart comprising multiple images of multiple cardiac cycleson the display screen.

In various embodiments, the method can comprise updating the multipleimages of a cardiac cycle at least once every thirty minutes.

In various embodiments, the method can comprise rendering a data set offield information on the display screen.

In various embodiments, the data set of field information can comprise adata set of voltage information.

In various embodiments, the data set of field information can correspondto the multiple cardiac locations and can be optionally associated withthe multiple cardiac locations on the display screen.

In various embodiments, the method can comprise displaying the data setof field information in a side-by-side arrangement with the data set ofsource information.

In various embodiments, the method can comprise displaying the data setof field information in an overlay arrangement with the data set ofsource information.

In various embodiments, the method can comprise displaying the data setof field information in an alternating arrangement with the data set ofsource information.

In various embodiments, the method can comprise producing calculatedinformation and electronically rendering the calculated information onthe display screen.

In various embodiments, the calculated information can be electronicallyrendered on the display screen in relation to one or more cardiaclocations.

In various embodiments, the calculated information can compriseinformation based on recordings from at least one ultrasound transducer.

In various embodiments, the calculated information can compriseinformation based on recordings from an array of ultrasound transducerspositioned in a cardiac chamber.

In various embodiments, the calculated information can comprise: cardiacchamber volume; cardiac wall thickness; average cardiac wall thickness;a cardiac chamber dimension; ejection fraction; cardiac output; cardiacflow rate; cardiac contractility; cardiac wall motion; or combinationsof two or more thereof.

In various embodiments, the calculated information can compriseinformation based on recordings from at least one electrode.

In various embodiments, the calculated information can compriseinformation based on recordings from an array of electrodes positionedin a cardiac chamber.

In various embodiments, the calculated information can comprise: voltageat a heart surface location; dipole state at a heart surface location;or combinations of two or more thereof.

In various embodiments, the calculated information can comprisequantitative information.

In various embodiments, the calculated information can be rendered onthe display in a form including: numerals; bar chart; pie chart; orcombinations of two or more thereof.

In various embodiments, the calculated information can comprisemathematically processed recorded information.

In various embodiments, the recorded information can compriseinformation recorded by a component including: one or more electrodes;one or more ultrasound transducers; one or more sensors; or combinationsof two or more thereof.

In various embodiments, the mathematical processing can compriseprocessing including: summing; averaging; integrating; differentiating;finding the mean; finding a maximum; finding a minimum; or combinationsof two or more thereof.

In various embodiments, the recorded information can compriseinformation recorded by one or more electrodes.

In various embodiments, the calculated information can compriseinformation including: dipole density information; surface chargedensity information; or combinations of two or more thereof.

In various embodiments, the calculated information can comprisemathematically processed dipole density or surface charge densityinformation.

In various embodiments, the mathematical processing can compriseprocessing including: summing; averaging; integrating; differentiating;finding the mean; finding a maximum; finding a minimum; or combinationsof two or more thereof.

In various embodiments, the recorded information can compriseinformation recorded by one or more ultrasound transducers.

In various embodiments, the calculated information can represent ameasure of heart contractility, and wherein the calculated informationis rendered on the display screen.

In various embodiments, the method can comprise identifying an undesiredcontractility decrease based on the calculated information.

In various embodiments, the calculated information can represent ameasure of heart enlargement, and wherein the calculated information isrendered on the display screen.

In various embodiments, the calculated information can represent ameasure of left atrial enlargement.

In various embodiments, the method can comprise identifying an undesiredheart enlargement based on the calculated information.

In various embodiments, the calculated information can comprise ameasurement of a change in patient information over a time period.

In various embodiments, the calculated information can comprise acomparison of patient information to a threshold.

In various embodiments, the method can comprise changing the appearanceof the calculated information on the display screen when the thresholdis exceeded.

In various embodiments, changing the appearance can comprise changing aparameter including: color; boldness; font; size; static or dynamicpresentation, or combinations of two or more thereof.

In various embodiments, the method can comprise activating an alert whenthe threshold is exceeded.

In various embodiments, the method can comprise electronically renderingadditional patient information on the display screen.

In various embodiments, the additional patient information can compriseinformation including: age; sex; race; height; weight; patient ID; orcombinations of two or more thereof.

In various embodiments, the additional patient information can compriseinformation including: blood pressure; heart rate; cardiac cycle length;pulse oximetry; respiration rate; or combinations of two or morethereof.

In various embodiments, the additional patient information can comprisequantitative information.

In various embodiments, the method can comprise representing thequantitative information on the display screen by a graphic elementincluding: numerals; bar chart; pie chart; graph; plot; or combinationsof two or more thereof.

In various embodiments, the method can comprise performing a therapeuticprocedure on the patient based on at least the determined sourceinformation.

In various embodiments, the therapeutic procedure can be performed basedon the rendered source information.

In various embodiments, the therapeutic procedure can comprise a cardiacablation procedure.

In various embodiments, the cardiac ablation procedure can compriseablating at least tissue of the left atrium.

In various embodiments, display of the data set of source information inrelation to the multiple cardiac locations can be a user interactivedisplay.

In various embodiments, user interactive display can be responsive to auser input to: pause, initiate, and/or record dynamic display of cardiacactivity; store, display, or output a data value associated with atleast one cardiac location; display or output an associated informationin a secondary window or frame providing graphical, numerical, ortextual information relating to cardiac activity represented by the dataset; zoom in on, zoom out from, and/or rotate a cardiac image; isolate aportion of the cardiac image; reveal a cross-section or slice throughthe cardiac image; or combinations of two or more thereof.

In various embodiments, associated information can include an ECG, EKG,or both.

In according with various aspects of the present invention, provided isa system configured and arranged to provide a graphical representationof cardiac information on a display screen. The system comprises: afirst receiver configured to receive cardiac geometry information and tocreate an anatomical model of the heart including multiple cardiaclocations; a second receiver configured to receive informationincluding: source information; field information; or combinations of twoor more thereof, and to determine a set of source informationcorresponding to cardiac activity at the multiple cardiac locations; anda display screen configured to provide the data set of sourceinformation in relation to the multiple cardiac locations.

In various embodiments, the source information can be data representing,at a location in 3D space, a physical property or properties discrete tothe specific location in 3D space.

In various embodiments, the source information can include dipoledensity data determined for a point on the surface of the heart.

In various embodiments, the source information can comprise: dipoledensity information; surface charge density information; pH information;temperature information; or combinations of two or more thereof.

In various embodiments, the system can comprise at least one ultrasoundtransducer configured to provide the cardiac geometry information to thefirst receiver.

In various embodiments, the at least one ultrasound transducer cancomprise multiple ultrasound transducers.

In various embodiments, the multiple ultrasound transducers can beconstructed and arranged in an expandable array.

In various embodiments, the system can comprise at least one sensorconfigured to provide the information received by the second receiver.

In various embodiments, the at least one sensor can comprise anelectrode.

In various embodiments, the at least one sensor can comprise: pH sensor;temperature sensor; or combinations of two or more thereof.

In various embodiments, the system can comprise an imaging deviceconfigured to provide the cardiac geometry information to the firstreceiver.

In various embodiments, the imaging device can comprise: a ComputedTomography apparatus; an MRI apparatus; an Ultrasound apparatus; amulti-electrode mapping catheter; a multi-transducer imaging cathetersuch as an imaging catheter comprising an array of ultrasoundtransducers; or combinations of two or more thereof.

In various embodiments, the system display of the data set of sourceinformation in relation to the multiple cardiac locations can be a userinteractive display.

In various embodiments, the system user interactive display can beresponsive to a user input to: pause, initiate, and/or record dynamicdisplay of cardiac activity; store, display, or output a data valueassociated with at least one cardiac location; display or output anassociated information in a secondary window or frame providinggraphical, numerical, or textual information relating to cardiacactivity represented by the data set; zoom in on, zoom out from, and/orrotate a cardiac image; isolate a portion of the cardiac image; reveal across-section or slice through the cardiac image; or combinations of twoor more thereof.

In various embodiments, the system associated information can include anECG, EKG, or both.

In various embodiments, the system can comprise a therapeutic deviceconfigured to treat the patient based on the source information providedon the display.

In various embodiments, the therapeutic device can be an ablationcatheter.

In accordance with aspects of the present invention, provided is acardiac information display method as shown and described in referenceto the figures herein.

In accordance with aspects of the present invention, provided is acardiac information display system as shown and described in referenceto the figures herein.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will become more apparent in view of the attacheddrawings and accompanying detailed description. The embodiments depictedtherein are provided by way of example, not by way of limitation,wherein like reference numerals refer to the same or similar elements.The drawings are not necessarily to scale, emphasis instead being placedupon illustrating aspects of the invention. In the drawings:

FIG. 1 illustrates a block diagram of an embodiment of a device fordetermining a database table of dipole densities d(y) and/or surfacecharge densities ρ(P′,t) of at least one heart chamber, in accordancewith aspects of the present invention;

FIG. 2 illustrates a flow chart of an embodiment of a preferred methodfor determining a database table of dipole densities and/or surfacecharge densities ρ(P′,t) of at least one heart chamber, in accordancewith aspects of the present invention;

FIG. 3 illustrates a schematic view of an embodiment of a system fordetermining a database table of dipole densities and/or surface chargedensities ρ(P′,t) of at least one heart chamber with help of the solidangle {acute over (ω)}(x,y), in accordance with aspects of the presentinvention;

FIG. 4 is an exemplary embodiment of a system for determining a databasetable of dipole and/or surface charge densities and for displaying suchdensity information, in accordance with aspects of the presentinvention;

FIG. 5A is a perspective view of the distal portion of a system fortreating a patient including an ablation catheter slidingly received bythe shaft of a diagnostic catheter and FIG. 5B is a perspective view ofthe system of FIG. 5A, with the ablation catheter in a bentconfiguration for treating a patient, in accordance with aspects of thepresent invention;

FIG. 5C is a perspective view of the distal portion of a system fordetermining a database of dipole and/or surface charge densities, inaccordance with aspects of the present invention;

FIG. 6 is an exemplary embodiment of a computer architecture formingpart of the system of FIG. 4, in accordance with aspects of the presentinvention;

FIG. 7 is an example embodiment of a method of determining and storingsurface charge densities, in accordance with aspects of the presentinvention;

FIG. 8 is an example embodiment of a method of determining and storingdipole densities, in accordance with aspects of the present invention;

FIG. 9 is an example embodiment of a method of displaying dipole and/orsurface charge densities, in accordance with aspects of the presentinvention;

FIG. 10 is an exemplary embodiment of a user interface display of dipoleand/or surface charge density information that can be generated on oneor more displays, in accordance with aspects of the present invention;

FIG. 11 is another embodiment of a user interface display of dipoleand/or surface charge density information that can be generated on oneor more devices, in accordance with aspects of the present invention;and

FIG. 12 is an example embodiment of a method of producing a model of aheart including the geometry of the cardiac surfaces, in accordance withaspects of the present invention.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

Various exemplary embodiments will be described more fully hereinafterwith reference to the accompanying drawings, in which some exemplaryembodiments are shown. The present inventive concept may, however, beembodied in many different forms and should not be construed as limitedto the exemplary embodiments set forth herein.

It will be understood that, although the terms first, second, etc. arebe used herein to describe various elements, these elements should notbe limited by these terms. These terms are used to distinguish oneelement from another, but not to imply a required sequence of elements.For example, a first element can be termed a second element, and,similarly, a second element can be termed a first element, withoutdeparting from the scope of the present invention. As used herein, theterm “and/or” includes any and all combinations of one or more of theassociated listed items.

It will be understood that when an element is referred to as being “on”or “connected” or “coupled” to another element, it can be directly on orconnected or coupled to the other element or intervening elements can bepresent. In contrast, when an element is referred to as being “directlyon” or “directly connected” or “directly coupled” to another element,there are no intervening elements present. Other words used to describethe relationship between elements should be interpreted in a likefashion (e.g., “between” versus “directly between,” “adjacent” versus“directly adjacent,” etc.).

The terminology used herein is for the purpose of describing particularembodiments only and is not intended to be limiting of the invention. Asused herein, the singular forms “a,” “an” and “the” are intended toinclude the plural forms as well, unless the context clearly indicatesotherwise. It will be further understood that the terms “comprises,”“comprising,” “includes” and/or “including,” when used herein, specifythe presence of stated features, steps, operations, elements, and/orcomponents, but do not preclude the presence or addition of one or moreother features, steps, operations, elements, components, and/or groupsthereof.

Spatially relative terms, such as “beneath,” “below,” “lower,” “above,”“upper” and the like may be used to describe an element and/or feature'srelationship to another element(s) and/or feature(s) as, for example,illustrated in the figures. It will be understood that the spatiallyrelative terms are intended to encompass different orientations of thedevice in use and/or operation in addition to the orientation depictedin the figures. For example, if the device in the figures is turnedover, elements described as “below” and/or “beneath” other elements orfeatures would then be oriented “above” the other elements or features.The device may be otherwise oriented (e.g., rotated 90 degrees or atother orientations) and the spatially relative descriptors used hereininterpreted accordingly.

To the extent that functional features, operations, and/or steps aredescribed herein, or otherwise understood to be included within variousembodiments of the inventive concept, such functional features,operations, and/or steps can be embodied in functional blocks, units,modules, operations and/or methods. And to the extent that suchfunctional blocks, units, modules, operations and/or methods includecomputer program code, such computer program code can be stored in acomputer readable medium, e.g., such as non-transitory memory and media,that is executable by at least one computer processor.

As used herein, the terms “subject” and “patient” refer to any animal,such as a mammal like livestock, pets, and preferably a human. Specificexamples of “subjects” and “patients” include, but are not limited, toindividuals requiring medical assistance, diagnosis, and/or treatment,for example, patients with an arrhythmia, such as atrial fibrillation(AF).

Surface charge density means surface charge (Coulombs) per unit area(cm²). A dipole, as such, is a neutral element, wherein one partcomprises a positive charge and the other part comprises the same, butnegative charge. A dipole or surface charge map could be considered torepresent an electric nature of cellular membranes better than voltagemaps, because in a biological environment, ion charges are notmacroscopically separated.

The terms “map” and “mapping” can include “electrical map”, “electricalmapping”, “anatomical map”, “anatomical mapping”, “device map” and“device mapping”, each of which is defined herein below.

The terms “electrical map” and “electrical mapping” can includerecording, processing and/or displaying electrical information, such aselectrical information recorded by one or more electrodes of the presentinvention. This electrical information includes, but is not limited to:cardiac or other tissue voltage measurements; cardiac or other tissuebipolar and/or unipolar electrograms; cardiac or other tissue surfacecharge data; cardiac or other tissue dipole density data; cardiac orother tissue monophasic action potentials; and combinations of these.

The terms “anatomical map” and “anatomical mapping” can includerecording, processing and/or displaying anatomical information, such asanatomical information provided by one or more ultrasound transducers ofthe present invention and/or one or more electrodes of the presentinvention. This anatomical information includes, but is not limited to:two or three dimensional representations of tissue such as one or morechambers of a heart; tissue wall thicknesses such as the thickness of anatrial or ventricular wall; distance between two tissue surfaces; andcombinations of these. In some embodiments, a dipole density map isprovided by using information provided by multiple electrodes andmultiple ultrasound transducers, such as is described in U.S. Pat. No.8,512,255 B2.

The terms “device map” and “device mapping” can include recording,processing and/or displaying of device distance information, such asinformation comprising the distance between a device or device componentand another object, such as tissue or another device or devicecomponent.

The term “patient information” can include physiologic and otherinformation related to the patient, including but not limited to sourceinformation and field information, as defined herein, that relates tothe patient's heart or other patient location. Patient information caninclude information which is derived from or is otherwise based onrecordings made by one or more sensors, such as one or more electrodes,ultrasound transducers and/or other sensors of the present invention.Patient information can include mathematically processed patientinformation, such as patient information that is averaged, summed,integrated, differentiated and/or otherwise mathematically processed tocreate new patient information. Patient information can include patientdemographic information, including but not limited to: age; sex; race;height; weight; and patient ID (e.g. an ID assigned to the patient by ahospital).

The term “cardiac information” can include patient physiologic and otherinformation related to the patient's heart, including but not limited tosource information and field information, as defined herein, thatrelates to the patient's heart and/or cardiac activity.

The systems and device of the present invention include one or moresensors or transducers, such as electrodes and ultrasound transducers.In various embodiments, any pair of electrodes can be constructed andarranged to provide distance information, such as the distance betweenthat pair of electrodes, or the distance between one of the electrodesand one or more proximate components (e.g., a component at a knowndistance from one or both of the electrodes in the pair). By deliveringand recording an electric signal between electrodes of known separationdistances, the signal can by processed and/or calibrated according toone or more known separation distances (e.g., the separation distancebetween two electrodes fixedly mounted to a rigid structure at apre-determined distance). Calibrated signal values can be combinedacross adjacent sets of electrode pairs to accurately estimate thedistance between any pair (e.g. any arbitrary pair of electrodes on anyone or more devices of the system) of electrodes for which theseparation distance is not known. Known and calculated separationdistances can be used as “reference” electrodes and combined totriangulate the unknown position of one or more “marker” electrodes,such as an electrode positioned on the present invention or on aseparate or external device and positioned proximate the presentinvention. The process of triangulation can be used to dynamicallylocalize the multi-dimensional position of any or all of the electrodeseither individually and/or as a combined entity in multi-dimensionalspace. Numerous distance measurement techniques can be used.

Further, any or all electrodes can be used to deliver electric energy,such as radiofrequency energy.

FIGS. 1-12 illustrate embodiments of devices, systems and methods thatcan be used for determining dipole (or surface charge) densities fromthe cardiac activity of a patient or subject. However, the presentinvention is not limited to these particular configurations. Thedescription will generally refer to “dipole densities,” which should beinterpreted to include, either additionally or alternatively, surfacecharge densities, unless otherwise stated, understood by those skilledin the art.

Referring now to FIG. 1, a block diagram of an embodiment of a dipoleand/or surface charge density system including device 100 configured todetermine a database table of dipole and/or surface charge densities ofat least one heart chamber of a patient is illustrated.

Device 100 can include a plurality of receivers, e.g., receivers (1),(2) . . . (n), configured to receive one or more types of informationfrom a patient, associated system, and/or other sensors. In thisembodiment, device 100 includes a first receiver 110 configured toreceive electrical potentials from a separate device, such as a deviceincluding a multi-electrode mapping catheter (e.g., placed in thecirculating blood within a chamber of the patient's heart). Device 100can further include a second receiver 120 configured to receive cardiacgeometry information (e.g., the geometric contour of the cardiac chamberwall), such as from an instrument including, but not limited to:Computed Tomography; MRI; Ultrasound; a multi-electrode mappingcatheter; a multi-transducer imaging catheter such as an imagingcatheter comprising an array of ultrasound transducers; and combinationsof these. In some embodiments, first receiver 110 receives informationfrom an array of electrodes placed in a chamber of the heart, and secondreceiver 120 receives information from an array of ultrasoundtransducers also placed in a chamber of the heart. In these embodiments,the electrodes and ultrasound transducers can be included on a singledeployable basket or other expandable assembly, such as is describedherebelow in reference to FIG. 5A or 5C. Alternatively or additionally,a standard geometry can be loaded representing a model of the heart,such as a model including the geometry of the cardiac chamber. In someembodiments, a receiver, e.g., receiver (n), can be provided to enabledevice 100 to receive information from electrodes or other types ofsensors that collect “source information,” e.g., temperature or pHsensors. As used herein, “source information” is data representing, at alocation in 3D space, a physical property or properties discrete to thespecific location in 3D space. As contrasted to “field information,”which, as used herein, is data representing, at a location in 3D space,a physical property or properties of a continuum extending through the3D space.

Device 100 further includes a dipole density module 130 which comprisesmathematical processing elements, such as a computer or other electronicmodule including software and/or hardware for performing mathematical orother calculations when executed by at least one computer processor.Dipole density module 130 receives electrical mapping information and/orother information (hereinafter “mapping information”) from firstreceiver 110 and cardiac geometry information from second receiver 120.Dipole density module 130 preferably uses one or more algorithms tocorrelate and/or otherwise process the received mapping and geometryinformation, such as to produce a database table of dipole and/orsurface charge densities (e.g. comprising multiple sequential data setsthat represent one or more phases of one or more cardiac cycles). Insome embodiments, the dipole and/or surface charge density information(or other source information) is updated at least once per second. Inother embodiments, the dipole density information (or other sourceinformation) is updated as least once per 10 seconds. Accordingly,dipole density module 130 can be configured to produce a database ordatabase table of dipole densities, surface charge densities, or both.

In some embodiments, the geometrical model of the cardiac chamber isprocessed by dipole density module 130 into multiple small polygons,such as multiple small triangles or other polygons (e.g., trapezoids,squares, rectangles, pentagons, hexagons, octagons, and so forth),hereinafter, collectively referred to as “triangles.” When the trianglesor other polygons are sufficiently small, the dipole and/or surfacecharge density at each triangle can be regarded as constant. In apreferred embodiment, a standard cardiac chamber of 4-6 cm diameter isdivided up into over 1000 triangles. In another preferred embodiment,the number of triangles determined by dipole density module 130 is basedon the size of the heart chamber. With the electrodes positioned in acardiac chamber by a clinician, such as an electrophysiologist, thepotentials at each electrode are recorded. Each triangle is seen by thecorresponding electrode under a certain solid angle.

As used herein, the term “solid angle” is the angle subtended by atriangle on the heart wall at a position x of observation. When viewedfrom location x, straight lines are drawn from point x to the boundariesof the triangle, and a sphere is constructed of radius r=1 with a centerof x. The straight lines then define the spherical triangle on thesurface of the sphere. The solid angle is proportional to the surfacearea of the projection of that object onto a sphere centered at thepoint x.

The dipole density module 130 computes the solid angle {acute over(ω)}(x,y) subtended by each triangle at position y on each electrode atposition x on the multi-electrode catheter. If the dipole density at thetriangle is d(y), the triangle contributes {acute over (ω)}(x,y) timesd(y) to the potential V(x) at the position x on the multi-electrodecatheter. The total measured potential V(x) is the sum resulting fromall the triangles. A detailed description is provided in reference toFIG. 3 herein below.

In some embodiments, dipole density module 130 can implement aprogressive algorithm that can be modified and/or refined in order toimprove spatial and/or time resolution of the database of dipoledensities that are produced. The dipole densities d(y) are obtained bysolving a linear system of equations. This calculation requires somecare to avoid numerical instabilities. Thereby a map of dipole and/orsurface charge densities can be created at corresponding time intervals.The synthesis of the maps generates a cascade of the activation sequenceof each corresponding heart beat (also referred to herein as “cardiaccycle”) that can be used to define the origin of the electricalactivity, arrhythmias and/or diagnose cardiac disease.

The measuring electrodes used can be placed in the blood flow in a heartchamber, a relatively homogeneous condition, such that the mathematicalanalysis is well applicable. In a preferred embodiment, skin electrodesare also implemented such that dipole density module 130 can use theinformation received from the skin electrodes to calculate and/orrecalculate the dipole densities for the cardiac wall. The spatialresolution which can be obtained by invasive (i.e., placed in thechamber) multi-electrode potential measurements correlates to the numberof electrodes that can be placed in any cardiac chamber, such as theLeft Atrium (LA). Skin placed electrodes, such as electrodes placed onthe thorax, are not space limited and can be used to enhancecalculations of the dipole densities. Application of electricalinformation measured from skin electrodes at known locations on thetorso can enhance the accuracy of dipole and/or surface charge densitycalculations by adding independent complementary information from theopposite side of the dipole layer, as compared to information obtainedfrom an electrode located within the heart chamber.

Due mainly to the inhomogeneous structure of the body, it is difficultto localize the actual sources of the skin electrode measuredpotentials. A highly complicated boundary value problem must be solvedwith boundary conditions that are poorly known, and previous attempts atdetermining the “action potential” from body surface ECG (alone) havenot been very successful. The badly defined boundary value problem canbe avoided by an additional measurement (in addition to the skinelectrode measurements) of the chamber-inserted multi-electrode array ofthe present invention. A small sinusoidal voltage V_(l) is applied toeach electrode l=1, . . . L on the electrode array in the heart, and theresulting voltages W_(k),k=1, . . . K is measured at the surfaceelectrodes. This yields the K×L transition matrix A_(kl)

$\begin{matrix}{W_{k} = {\sum\limits_{l = 1}^{L}{A_{kl}{V_{l}.}}}} & (1)\end{matrix}$

Calculating solid angles produces the linear transformation B_(ln)between the electrode array potentials V_(l) and the dipole densitiesd_(n), n=1, . . . N of N regions of the heart wall:

$\begin{matrix}{V_{l} = {\sum\limits_{n = 1}^{N}{B_{l\; n}{d_{n}.}}}} & (2)\end{matrix}$

N is chosen to be N=K+L where K is the number of surface electrodes andL is the number of internally placed array electrodes.

Substituting equation (2) into (1) we have:

$\begin{matrix}{W_{k} = {\sum\limits_{l = 1}^{L}{\sum\limits_{n = 1}^{N}{A_{kl}B_{l\; n}{d_{n}.}}}}} & (3)\end{matrix}$

Therefore, by simultaneous measuring of the potentials of the cardiacactivity with all K+L electrodes, N=K+L dipole densities of N regions onthe heart wall can be calculated. This method yields a higher spatialresolution than the L array electrodes alone. In the solution of thelinear system of equations (2)+(3), regularization techniques must beused (e.g. Tikhonov regularization and its modifications) in order toavoid numerical instabilities.

In some embodiments, other types of information can be captured, such asa temperature from a temperature sensor (e.g. a thermocouple) or pH froma pH sensor. The associated sensor can be placed at multiple locationsalong a cardiac surface while data is recorded. Module 130 can be usedto correlate the recordings provided by the sensor to the anatomicalinformation.

Referring now to FIG. 2, an embodiment of a preferred method fordetermining a database table of dipole (and/or surface charge) densitiesof at least one heart chamber of a patient is illustrated. In Step 10, amulti-electrode array catheter device is placed within the correspondingheart chamber. In Step 20, a model of the heart including the geometryof the corresponding heart chamber is created (i.e. electronicallycreated). In some embodiments, the model of the heart is created inrelation to the multi-electrode array position. In some embodiments, themodel of the heart comprises a static model comprising the geometry ofone or more cardiac chambers representing that geometry at oneparticular reference point in a cardiac cycle (e.g. temporally proximatethe end of systole or the end of diastole). The geometry of the staticheart model can comprise a single image (e.g. created one time) or itcan be updated over time (e.g. updated by capturing chamber geometryinformation at the same reference point in multiple sequential ornon-sequential cardiac cycles). In some embodiments, the static heartmodel is updated at least once every thirty minutes. Alternatively oradditionally, the model of the heart comprises a dynamic model (alsoreferred to as a “beating heart model”). The dynamic model can comprisethe cardiac geometry at multiple reference points of a single cardiaccycle (i.e. multiple images for a single heart beat) or it can beupdated over time (e.g. by capturing sets of images at similar referencepoints in the cardiac cycle over multiple heart beats). In someembodiments, the dynamic heart model is updated at least 30 times persecond (e.g. to provide a continuous image of the heart at 30 frames ofvideo per second). In other embodiments, the dynamic heart model isupdated at least once every 100 milliseconds, at least once everysecond, at least once every minute, or at least once every thirtyminutes. In some embodiments, source information and/or fieldinformation is updated at least 30 times per second (e.g. to provide acontinuous image of changing source information and/or field informationat 30 frames of video per second). In other embodiments, sourceinformation and/or field information is updated at least once every 100milliseconds, at least once every second, at least once every minute, orat least once every thirty minutes.

In some embodiments, the heart chamber geometry is provided byimage-producing sensors (e.g. ultrasound sensors) from the same catheterdevice or a separate catheter device placed in the heart chamber.Alternatively or additionally, the model of the heart including heartchamber geometry is created (i.e. electronically created) frominformation provided by an imaging device external to the patient (e.g.a fluoroscope, computer tomography device, ultrasound imager, MRI)before and/or after the multi-electrode array of electrodes has beenplaced in the heart chamber. The surface of the geometry of thecorresponding heart chamber model can be divided into small triangles,typically at least 1000 small triangles.

In Step 30, the dipole density d(y) can be calculated (i.e.electronically determined) from the measured potential values and thecalculated solid angles. The measurements can be repeated successivelyduring the cardiac cycle, such as to achieve sufficient resolution overtime. The information of the time dependent dipole densities can bedepicted as an activation map of the corresponding heart chamber for thegiven heartbeat. The information can be used to diagnose and/or treat apatient with a cardiac disease or disorder, such as atrial fibrillationor other cardiac arrhythmia. Alternatively or additionally, the surfacecharge density can be calculated in Step 30. In either or both cases,the dipole and/or surface charge densities can be stored in a databaseor database table, in Step 30.

In various embodiments, the information can be used to determine cardiacwall treatment locations for lesion creation to treat an arrhythmia,such as a lesion created in the Left or Right atrium, by an RF,microwave, laser, ultrasound and/or cryogenic ablation catheter. In someembodiments, the multiple electrode mapping array is placed in aventricle and the dipole densities are determined for the ventricularwall, such as to detect ischemia or quantify myocardial function.

Referring now to FIG. 3, an embodiment of a system for determining adatabase table of dipole densities and/or other information of at leastone heart chamber of a patient is illustrated.

System 300 includes device 100, which can be configured to create adatabase (or table) of dipole densities d(y) based on electricalpotential measurements within the heart chamber and image informationrelating to the heart chamber, as has been described herein above.Alternatively or additionally, device 100 can be configured to create adatabase of other information, such as other local information regardingsurface charge densities, temperature and/or pH levels at a cardiacsurface. System 300 further includes imaging unit 220, which isconfigured to provide a two or three-dimensional image of the heartchamber relative to information provided by device 100. Imaging unit 220can perform at least one of fluoroscopy, Computed Tomography, MRI and/orultrasound imaging, as examples of imaging technologies. Imaging unit220 can produce any form of real or virtual models of the cardiacchambers, such that a mesh analysis (e.g. using triangles, polygons,etc.) is possible.

System 300 further includes mapping catheter 310, which includes shaft311, shown inserted into a chamber of a patient's heart, such as theLeft Atrium (LA). At the proximal end of shaft 311 is handle 312. At thedistal end of shaft 311 is an array 315 including multiple electrodes316 and/or multiple other sensors configured to record local informationand/or field information. Array 315 is shown in a basket construction,but numerous other constructions can be used including multipleindependent arms, spiral arrays, electrode, ultrasound sensor and/orother sensor-covered balloons, and other constructions configured toplace multiple sensors and/or transducers into a two orthree-dimensional arrangement. In a preferred embodiment, any catheterwith a multi-dimensional array of electrodes or other sensors can beused to supply the mapping or other information to device 100. Invarious embodiments, alternatively or additionally, the electrodesand/or sensors can include sensors to sense other types of “sourceinformation,” e.g., temperature and pH, as examples. Handle 312 caninclude one or more controls, not shown but such as one or more controlsto steer shaft 311 and/or control one or more sensors or transducers ofarray 315, such as to activate one or more electrodes 316.

In some embodiments, catheter 310 can include one or more types ofimaging transducers, such as ultra-sound transducers (USTs) built intocatheter 310 or array 315, such as is described herebelow in referenceto catheter 500 of FIG. 5A or catheter 500′ of FIG. 5C. Such imagingtransducers could be used to obtain imaging information to generate,maintain, update and/or augment the image of the heart, in conjunctionwith imaging unit 220.

Electrodes 316 are connected to wires, not shown, but travelingproximally, passing through handle 312 to cable 317, which iselectrically connected to a mapping unit 210, such as anelectrocardiogram (ECG) unit. Mapping unit 210 includes a monitor fordisplaying information, such as the potentials recorded by electrodes316, as well as the dipole density or other information produced bydevice 100. In an alternative embodiment, device 100 further includes amonitor, not shown, but configured to display one or more of: dipoledensity information; surface charge information; potentials recorded byelectrodes 316; information recorded by one or more sensors such as oneor more temperature and/or pH sensors; and cardiac chamber contours andother geometry information. In a preferred embodiment, dipole densityand/or recorded potentials information is shown in reference to amulti-dimensional representation of the heart chamber into whichcatheter 310 is inserted. In an alternative embodiment, imaging unit 220can include a device configured to create an image of the cardiacchamber from signals recorded from an sensor array catheter, such ascatheter 310 of FIG. 3, catheter 500 of FIG. 5A or catheter 500′ of FIG.5C.

System 300 can include a device for treating a cardiac arrhythmia, suchas ablation source 230, which is electrically attached to electrodes 316via cable 318. Alternatively or additionally, ablation source 230 can beoperably attached (e.g. via wires, fluid delivery tubes and/or opticalfibers) to a different ablation catheter, such as a single or multipleablation element catheter configured to deliver ablation energy such asRF energy, microwave energy, laser energy, ultrasound energy, cryogenicenergy, or other tissue disrupting energy.

As shown in FIG. 3, triangle T1, defined by device 100, is at locationY. Array 315 includes multiple electrodes 316, such as electrode 316 apositioned at location X. The geometric relationship between triangle T1and location X is defined by the solid angle, angle {acute over(ω)}(X,Y). Device 100 includes dipole density module 130 such that eachtriangle at location y contributes {acute over (ω)} (x,y) times thedipole density d(y) to the potential V(x) at the position x for eachelectrode of array 315. Solid angle {acute over (ω)}(x,y), as definedabove, corresponds to the triangle at a location y and the electrode atpositions x on the multi-electrode array 315. The dipole density module130 of device 100 determines from the total measured potential V(x),which is the sum resulting from all the triangles defined by device 100,the desired dipole density d(y).

When sufficient potential values V(x) are measured (e.g. from 10 to10,000 with increasing number of measured potentials providing moreaccurate and/or spatially detailed results), the dipole density d(y) atmany equally distributed regions y on the cardiac wall is calculated bysolving a linear equation system. By interpolation of the measuredpotentials (e.g. with help of splines) their number of regions used inthe calculation can be increased. The solid angle {acute over (ω)}(x,y)of a region is the sum of the solid angles of the individual trianglesin the region on the cardiac wall. This calculation of dipole densityresults, such as via an automatic computer program forming at least partof dipole density module 130.

In some embodiments, the results are presented in a visual, anatomicalformat, such as depicting the dipole densities on a geometric image ofthe cardiac wall in relation to time (t). This format allows aclinician, such as an electrophysiologist, to determine the activationsequence on the cardiac wall, such as to determine treatment locationsfor a cardiac arrhythmia. The results can be shown on a display ofmapping unit 210, or on a separate unit such as a display included withdevice 100, display not shown but preferably a color monitor. In apreferred embodiment, the device of the present invention is implementedas, or includes, a software program that is executable by at least oneprocessor. The software program can be integrated into one or more of:an ECG system; a cardiac tissue ablation system; an imaging system; acomputer; and combinations of these.

In some embodiments, the multi-electrode catheter 310 includes at least10 electrodes 316 and/or other sensor, configured to provide localinformation and/or field information in relation to a multi-dimensionalrepresentation of a heart. The electrodes 316 are preferably positionedin a spherical geometry, such as a spherical geometry created in abasket catheter. Elliptical electrode array geometries can be used, suchas those provided in the Ensite Array Catheter, manufactured by St. JudeMedical of St. Paul Minn. In an alternative embodiment, multiplecatheters are inserted into the heart chamber to provide the multipleelectrodes.

In some embodiments, the electrodes 316 of the multi-electrode mappingarray 315 are repositioned during the method of determining dipoledensities. Repositioning of electrodes 316 and/or other sensors ortransducers of array 315 can be beneficial to increase the number ofmeasured potential values, if electrode 316 positions are known.Therefore, repositioning is in concordance with adjustment of thegeometry map in relation to the multi-electrode mapping array 315.

In some embodiments, array 315 further comprises one or moretransducers, such as one or more ultrasound transducers (USTs), asdescribed variously herein. Also in some embodiments, eitheralternatively or in addition to the electrodes 316, array 315 caninclude non-electrode sensors, such as temperature sensors and/or pHsensors.

FIG. 4 shows an example embodiment of a system 400 configured todetermine a database table of dipole and/or surface charge densities ofat least one heart chamber of a patient, e.g., as an embodiment ofsystem 300 above. That is, system 400 can be considered to be a somewhatsimplified version of system 300, used to describe an approach fordetermining dipole and/or surface charge densities using voltagemeasurements representing cardiac activity. System 400 can be used tomap activity of a heart 452 of a patient 450, e.g., a human. In order togenerate a map of surface charge densities (e.g., a surface chargedensity distribution), the geometry of the given heart chamber isdetermined or obtained in any of a variety of manners such as thosedescribed herein. The multi-dimensional geometry of the cardiac chambercan be assessed, in various embodiments, by currently available andcommon mapping systems (so-called locator systems) or, alternatively, byintegrating anatomical data from CT/MRI scans.

System 400 can include a computer 410 having known types of inputdevices and output devices, such as a display 420 and printer 430, and aprobe system 440. For the measurement of potentials, contact and/ornon-contact mapping methods can be used. The mapping methods can useprobe electrode system 442, which is connected to the computer 410 via acable and forms part of probe system 440 as shown in FIG. 4. Probesystem 440 can take the form of, or include, a catheter. The computer410 can be configured to include at least one processor and computerstorage device, comprising a set of executable functional modules thatperform various tasks to determine dipole and/or surface charge densityusing cardiac potential information from the probe system 440.

The probe electrode 442 can take the form of a multi-electrode arraywith elliptic or spherical shape, in some embodiments. The sphericalshape of such an array can have certain advantages for the subsequentdata analysis. Alternatively or additionally, other types or evenseveral independent electrodes could be used to measure V_(e) (i.e., thevoltage on the endocardium). For example, when considering a cardiaccavity within the endocardium and taking a probe electrode with asurface S_(p), which is located in the blood (i.e. non-contacting), itis possible to measure the potential V(x,y,z) at point x,y,z on thesurface S_(p). In order to calculate the potential at the endocardialsurface S_(e) the Laplace equation:

$\begin{matrix}{{\Delta \; V} = {{\left( {\frac{\partial^{2}}{\partial x^{2}} + \frac{\partial^{2}}{\partial y^{2}} + \frac{\partial^{2}}{\partial z^{2}}} \right)V} = 0}} & (4)\end{matrix}$

needs to be solved, wherein V is the potential and x,y,z denote thethree dimensional coordinates. The boundary conditions for this equationare V(x,y,z)=V_(p)(x,y,z) on S_(p), wherein V_(p) is the potential onsurface of the probe S_(p).

The solution is an integral that allows for calculating the potentialV(x′y′z′) at any point x′y′z′ in the whole volume of the heart chamberthat is filled with blood. For calculating said integral numerically, adiscretization of the cardiac surface is necessary and the so calledboundary element method (BEM) can be used.

The boundary element method is a numerical computational method forsolving linear integral equations (i.e. in surface integral form). Themethod is applied in many areas of engineering and science, includingfluid mechanics, acoustics, electromagnetics, and fracture mechanics.

The boundary element method is often more efficient than other methods,including the finite element method. Boundary element formulationstypically give rise to fully populated matrices after discretization.This result means that the storage requirements and computational time,using BEM, will tend to grow according to the square of the problemsize. By contrast, finite element matrices are typically banded(elements are only locally connected) and the storage requirements forthe system matrices typically grow quite linearly with the problem size.

With the above in mind, all potentials V_(p) (x1′,y1′,z1′) on thesurface of the probe can be measured. To calculate the potential V_(e)on the wall of the heart chamber, the known geometry of the surface ofthe heart chamber are divided into discrete parts to use the boundaryelement method. The endocardial potentials V_(e) are then given by alinear matrix transformation T from the probe potentials V_(p):V_(e)=TV_(p).

After measuring and calculating one or more electric potential(s) V_(e)of cardiac cells in one or more position(s) P(x,y,z) of the at least onegiven heart chamber at a given time t, the surface charge and/or dipoledensities are determined. The surface charge density and the dipoledensity are related to potential according to the following two Poissonequations:

$\begin{matrix}{{\Delta \; V_{e}} = {{\rho (P)}{\delta_{S_{e}}(P)}}} & (5) \\{{\Delta \; V_{e}} = {\frac{\delta}{\partial n}\left( {\upsilon \; {\delta_{S_{e}}(P)}} \right)}} & (6)\end{matrix}$

wherein ρ(P) is the surface charge density in position P=x,y,z, δ_(s)_(e) (P) is the delta-distribution concentrated on the surface of theheart chamber S_(e) and ν is the dipole density.

A relationship exists between the potential V_(e) on the surface of thewall of the heart chamber and the surface charge (7) or dipole densities(8).

$\begin{matrix}{{V_{e}(P)} = {{- \frac{1}{4\pi}}{\int_{S_{e}}{\frac{\rho \left( P^{\prime} \right)}{{P^{\prime} - P}}d\; {\sigma \left( P^{\prime} \right)}}}}} & (7) \\{{V_{e}(P)} = {\frac{1}{4\pi}{\int_{S_{e}}{{\upsilon \left( P^{\prime} \right)}\frac{\partial}{\partial n_{P^{\prime}}}\frac{1}{{P - P^{\prime}}}d\; {\sigma \left( P^{\prime} \right)}}}}} & (8)\end{matrix}$

(For a review see Jackson JD. Classical Electrodynamics, edition, Wiley,New York 1975.)

The boundary element method again provides a code for transforming thepotential V_(e) in formulas 7 and 8 into the desired surface chargedensities and dipole densities, which can be recorded in a database ofsurface charge densities and/or dipole densities.

In another embodiment, the electric potential(s) V_(e) is (are)determined by contact mapping. In this case the steps for calculatingthe electric potential V_(e) are not necessary, because the directcontact of the electrode to the wall of the heart chamber alreadyprovides the electric potential V_(e).

In an example embodiment, the probe electrode comprises a shape thatallows for calculating precisely the electric potential V_(e) and, thus,simplifies the calculations for transforming V_(e) into the desiredcharge or dipole densities. That is, the geometry of the electrode canbe ellipsoidal or spherical in such an embodiment.

In order to employ the method for determining a database (or table) ofsurface charge densities of at least one given heart chamber in thecontext of the present invention, a system comprising at least thefollowing can be used:

-   -   a) one unit for measuring and recording electric potentials V at        a given position P(x,y,z) on the surface of a given heart        chamber (contact mapping) or a probe electrode positioned within        the heart, but without direct wall contact (noncontact mapping)    -   b) one aid-converter for converting the measured electric        potentials into digital data,    -   c) one memory (e.g., computer memory) to save the measured        and/or transformed data, and    -   d) one processor unit for transforming the digital data into        digital surface charge density or dipole density data.

It is noted that numerous devices for localizing and determiningelectric potentials of cardiac cells in a given heart chamber byinvasive and non-invasive methods are well known in the art and havebeen employed by medical practitioners over many years. Hence, thepresent invention is not limited to any particular types of electrodesor other sensors or transducers. Instead, the invention provides a newand advantageous processing of the available data that will allow for anincrease in precision, accuracy and spatial resolution of cardiacactivation mapping when compared to prior art systems based on electricsurface potentials in the heart only. The present invention providesenhanced diagnostic means for diagnosing cardiac diseases and disorders(e.g. arrhythmias) and other electric status of heart cells includingmetabolic and functional information.

Catheters and other devices as used in the context of the presentinvention can include numerous forms of diagnostic catheters such ascatheters including one or more electrodes, or therapeutic catheterssuch as tissue ablation catheters, such as, for example, the cathetersdescribed in U.S. patent application Ser. No. 14/422,941, filed Feb. 5,2015, entitled Catheter System and Methods of Medical Use of Same,Including Diagnostic and Treatment Uses for the Heart. Catheters can beintroduced percutaneously into a patient's heart, such as to recordelectrical activity, measure distances between structures, or deliverenergy. External devices and systems can be included, such as bodysurface electrodes used to record an electrical signal and/or deliver anelectric signal, or visualization devices such as external ultrasound orfluoroscopic imaging systems. Any of these catheters or other devicescan include one or more electrodes, one or more ultrasound transducers,and/or one or more other sensors or transducers. These electrodes,ultrasound transducers, and/or other sensors or transducers can bepositioned at any location on the device, for example at a distal orproximal portion of the device, and can be positioned internal orexternal to a patient's body.

Any or all of the ultrasound transducers can be used to measure adistance between the transducer and a surface, as is known in the art.One example includes measuring the distance between the ultrasoundtransducer and a wall of the cardiac chamber. Another example includesmeasuring the distance between the ultrasound transducer and a componentof the same or a separate device.

Any or all of the electrodes of such catheters can be used to recordelectric “signals” (e.g. voltages and/or currents) at or between theelectrode locations. Recorded electric signals can be used to mapelectrical activity of tissue, such as when an electrode is positionedaway from tissue (e.g. in the circulating blood) or when an electrode isin contact with tissue. Algorithms, such as those described hereabove,can be used to correlate recorded signals at multiple non-contactinglocations to signals present at one or more tissue locations. The mappedelectrical activity and/or other electrical signals can be furtherprocessed (e.g. in terms of sources of charge and charge density andcorrelated with various physiologic parameters related to the functionof the heart) and the mapped electrical activity and other recorded andcalculated information can be provided visually to one or more operatorsof the system of the present invention.

Any or all of the electrodes can be used to deliver and/or recordelectric signals that are generated by the system. Such deliveredsignals can be emitted from any one or more electrodes, and can bedelivered between any two or more electrodes. Recorded signals cancomprise a signal present at a single electrode location or at multipleelectrode locations (e.g. a signal representing a comparison of two ormore signals present at two or more electrode locations). Recordedsignals can be measured, for example, synchronously or asynchronously interms of voltage and/or current. Recorded signals can be furtherprocessed in terms of, for example, resistive and reactive components ofimpedance and/or the combined magnitude of impedance with any originalor processed signal “values” (e.g. those represented by a parameterselected from the group consisting of: instantaneous amplitude; phase;peak; Root-Mean-Square; demodulated magnitude; and combinations ofthese).

Referring now to FIGS. 5A and 5B, perspective views of the distalportion of a system for diagnosing and/or treating a heart disease ordisorder, such as atrial fibrillation and/or ventricular tachycardia, isillustrated. The system can be an embodiment of array 315 of FIG. 3,array 530′ of FIG. 5C, and/or probe electrode system 442 of FIG. 4, orportions thereof. FIG. 5A illustrates an ablation catheter slidinglyreceived by the shaft of a diagnostic catheter and FIG. 5B illustratesthe ablation catheter of FIG. 5A in a bent configuration, in accordancewith aspects of the present invention.

The probe system 440 includes a diagnostic catheter 500 which isconstructed and arranged for insertion into a body location, such as thechamber of a heart. Catheter 500 includes shaft 502, typicallyconstructed of sufficiently flexible material to allow insertion throughthe tortuosity imposed by the patient's vascular system. On the distalportion of shaft 502 is an expandable assembly 530, which includes aplurality of electrodes 541 coupled thereon. Additionally, a pluralityof ultrasound transducers 551 are coupled to expandable assembly 530 inthis embodiment. Electrodes 541 and USTs 551 are each electricallyattached to one or more wires which travel proximally within shaft 502,connecting to one or more receivers such as receivers 110 and 120described hereabove in reference to FIG. 1. In some embodiments,catheter 500, expandable assembly 530, electrodes 541 and/or ultrasoundtransducers 551 are constructed and arranged as the similar componentsdescribed in Applicant's co-pending U.S. patent application Ser. No.14/003,671, entitled Device and Method for the Geometric Determinationof Electrical Dipole Densities on the Cardiac Wall, filed Sep. 6, 2013,the entirety of which is incorporated herein by reference. The numberand pattern of electrodes (or other sensors) and USTs can be differentin different embodiments; the invention is not limited to the embodimentdepicted in FIGS. 5A and 5B which includes a pattern of two electrodes541 between pairs of USTs 551. In some embodiments, a repeating patternof a single electrode 541 followed by a single UST 551 and so on isincluded, such as is shown in FIG. 5C. In some embodiments, catheter 500can include other types of electrodes or other sensors, e.g.,temperature and/or pH sensors, either in addition to or as analternative to the electrodes shown.

The system further comprises an ablation catheter 520, which includesshaft 522. Shaft 522 includes at least one ablation element 561, locatedat a tip or otherwise on a distal portion of shaft 522. Ablation element561 is constructed and arranged to deliver energy to tissue, such aswhen ablation catheter 520 is attached to a source of energy.

Shaft 502 includes a lumen 526 traveling from at least a proximalportion of shaft 502 (e.g. from a handle, not shown but typicallypositioned on shaft 502's proximal end) to a distal portion of shaft 502(e.g. to shaft 502's distal end). Shaft 502 of ablation catheter 520 andlumen 526 of diagnostic catheter 500 are constructed and arranged toallow shaft 522 of ablation catheter 520 to be slidingly received bylumen 526. Lumen 526 can be further configured to slidingly receiveadditional catheters or other elongate devices, such as prior toinsertion of diagnostic catheter 500 into a body, or after diagnosticcatheter 500 has been inserted into a body.

Diagnostic catheter 500 can be used for mapping tissue such as an organor portion of an organ (e.g. a portion of a heart wall).Multi-dimensional anatomical mapping information collected by diagnosticcatheter 500 can be used by the system (e.g., computer system 400) tocreate a multi-dimensional display of an anatomical location of which atleast a portion is to be treated by ablation catheter 520. Diagnosticcatheter 500 can be coupled to a computer system, e.g., computer system400) configured to display anatomical mapping information generated bydiagnostic catheter 500, such as volumes, locations, shapes, contours,and movement of organs, nerves, and other tissue within the body.Diagnostic catheter 500 can be coupled to the computer system 400 todisplay the electrical mapping information generated by diagnosticcatheter 500, such as to display dipole mapping or other information ashas been described above. Additionally, the location of ablationcatheter 520 or other inserted devices can be displayed, such as theirposition relative to tissue or diagnostic catheter 500. For example,diagnostic catheter 500 can be used to map the heart, while ablationcatheter 520 can be directed to a tissue location in the heart targetedfor treatment (e.g. targeted for treatment based on information providedby diagnostic catheter 500 and/or another component of system 400). Forexample, ablation catheter 520 can be configured to ablate cardiactissue to treat a patient suffering from a cardiac arrhythmia, such asatrial fibrillation, atrial flutter, supraventricular tachycardias(SVT), Wolff-Parkinson-White syndrome, and ventricular tachycardias(VT). An ablation catheter will be described herein as a form of atreatment device for purposes of conveying aspects of the invention, buta different type of treatment device (e.g., a pacing device; adefibrillation device; a stent delivery device; a drug delivery device,a stem cell delivery device, or the like) can be used in otherembodiments in combination with diagnostic catheter 500. In someembodiments, one or more of these treatment devices is inserted througha lumen of diagnostic catheter 500.

In some embodiments, the system is configured to access the left atriumof the patient while utilizing a single transseptal puncture throughwhich all the catheter components of system access the left atrium (andsubsequently the left ventricle in some cases). In other embodiments,the system is configured to access the left ventricle of the patientwhile utilizing a single crossing of the aortic valve through which allthe catheter components of the system access the left ventricle (andsubsequently the left atrium in some cases).

The system can include sheath 504, for example a standard access sheath,such as a standard transseptal access sheath. In some methods, sheath504 can be inserted through the atrial septum and into the left atrium,followed by the insertion of diagnostic catheter 500 through a lumen ofsheath 504. Subsequently, ablation catheter 520 can be inserted throughlumen 526 of diagnostic catheter 500. In other methods, sheath 504 isinserted into the left atrium, followed by the simultaneous insertion ofdiagnostic Catheter 500 and ablation catheter 520 (e.g. diagnosticcatheter 500 is inserted with ablation catheter 520 residing at leastpartially within lumen 526). In some embodiments, sheath 504 cancomprise a steerable sheath. Shaft 502 comprises a diameter along themajority of its length such as to be slidingly received by sheath 504.In some embodiments, shaft 502 comprises a diameter less than or equalto 15 Fr. In some embodiments, diagnostic catheter 500 and/or ablationcatheter 520 can be steerable, so that manual, semi-automatic orautomatic steering can be performed by an operator and/or a roboticcontrol assembly of the system, as shown in FIG. 5B.

Diagnostic catheter 500 can be positioned in the left atrium and canprovide information selected from the group consisting of: electricalinformation, such as voltage information (e.g. voltage information whichis analyzed to produce surface charge information); anatomical geometryinformation, such as heart wall surface information or heart wallthickness information; other physiologic and anatomical information,such as those described herein; and combinations of these. Shaft 502 ofdiagnostic catheter 500 can be configured to be inserted into the heartvia the venous system, for example a vein in a leg or a vein in a neck.Shaft 502 can include a braid within its outer and inner surfaces, notshown but typically a braid of plastic or metal fibers that enhance thestructural integrity and performance of shaft 502. In some embodiments,the braid of shaft 502 can include conductors (e.g. one or moreconductors connected to an electrode 541 and/or an ultrasound transducer551).

As described above, diagnostic catheter 500 includes lumen 526 extendingfrom a proximal portion to a distal portion of shaft 502, for examplefrom a proximal end to a distal end of shaft 502 so as to allow aseparate catheter or other elongate device to be inserted therethrough,such as ablation catheter 520, as shown. Alternatively or additionally,the inserted catheter or other elongate device can include a diagnosticcatheter, such as a diagnostic catheter configured to record signalsfrom a location selected from the group consisting of: the left atrium;the right atrium; the Bundle of HIS; the right ventricular apex; apulmonary vein; the coronary sinus. Alternatively or additionally, theinserted catheter can comprise another catheter device.

Diagnostic catheter 500 can include expandable assembly 530, which ispositioned at the distal end of shaft 502—here in the form of a basketarray. As illustrated, expandable assembly 530 includes an array ofsplines 531, each spline 531 having proximal segment 532, middle portion534, and distal segment 533. Proximal segment 532 of each spline 531connects to shaft 502, via connection point 527. The distal ends of eachspline 531 connect in a circumferential ring configuration to formopening 535. Opening 535 allows a device to pass through, such as adevice inserted into lumen 526, for example shaft 522 of ablationcatheter 520. In some embodiments, expandable assembly 530 can includeone or more guide elements configured to guide a device through opening535.

Expandable assembly 530 can be constructed and arranged to be positionedin the expanded Shape shown in FIGS. 5A and 5B. The expanded geometry ofassembly 530, including at least two or more splines 531 in an expandedor partially expanded state (hereinafter “expanded state”), can bedescribed as a “basket” having a substantially hollow center and spacesbetween adjacent splines 531. In the illustrated embodiment, the basketis spherical, but can include any suitable shape, for example anellipsoid or other symmetric or asymmetric shape. Thus, in otherembodiments, assembly 530 can comprise different shapes or combinationof shapes, such as an array of splines 531 where two or more splines 531comprise similar or dissimilar shapes, dimensions or configurations. Insome embodiments, two or more splines 531 include a varied radius ofcurvature.

Expandable assembly 530 can be biased in an expanded or non-expandedstate. In an example embodiment, assembly 530 can be self-expanding suchthat splines 531 are resiliently biased in the curved geometry shown inFIGS. 5A and 5B. Assembly 530 can automatically expand when assembly 530exits the distal end of sheath 504, such as by advancement of shaft 522and/or retraction of sheath 504. Alternatively, assembly 530 can bemanually expanded, for example via retraction of a rod (not shown) thatslides within shaft 502 and is connected to distal end of assembly 530.

Splines 531 can be constructed of a material selected from the groupconsisting of: one or more thermoplastic polymers such as polyetherblock amide, polyurethane and/or polyether ether ketone; one or more ofthermoset polymers such as silicon and/or tetrafluoroethylene; one ormore metals such as stainless steel and/or shape memory alloys such asnickel titanium alloy; one or more shape memory polymers such as tripleshape acrylic; and combinations of these. Generally, any of a number ofmaterials or compositions that are biocompatible, flexible or bendable,and possess any necessary application specific electrical properties canbe used for splines 531.

Splines 531 can include one or more electrodes 541 and/or one or moreultrasound transducers 551 arranged in any combination. For example, insome embodiments, one or more of the following configurations isincluded: each spline 531 includes at least four, six or eightelectrodes 541; each spline 531 includes at least four, six or eightultrasound transducers 551; and combinations of these. In someembodiments, at least one electrode 541 is positioned between twoultrasound transducers 551 on a single spline 531 (such as in thealternating pattern shown in FIG. 5C). In some embodiments, at least twoelectrodes 541 are positioned between two ultrasound transducers 551 ona single spline 531.

Each spline 531 can include a similar or dissimilar arrangement ofelectrodes 541 and/or ultrasound transducers 551 such as an adjacentspline 531 or any other spline 531 in assembly 530. In some embodiments,assembly 530 includes eight splines 531, where each spline 531 caninclude two to eight electrodes 541 and two to eight ultrasoundtransducers 551. In some embodiments, assembly 530 includes six splines531, where each spline 531 can include eight electrodes 541 and eightultrasound transducers 551. In some embodiments, one or more splines 531include a number of electrodes 541 that comprises a quantity within oneof the quantity of ultrasound transducers 551 that are included on thatspline 531. For example, a spline 531 can include seven electrodes 541and either six or eight ultrasound transducers 551. In some embodiments,a set of electrodes 541 and ultrasound transducers 551 can be arrangedin an alternating arrangement, such that one or more single ultrasoundtransducers 551 lies between two electrodes 541. In some embodiments,some sets of electrodes 541 and ultrasound transducers 551 can bearranged such that one or more single electrodes 541 is positionedbetween two ultrasound transducers 551.

Electrodes 541 can be configured to record electric signals such asvoltage and/or current signals. The system can utilize the recordedsignals to produce electrogram information; dipole mapping information;surface charge information; distance information such as the distancebetween any device and/or component of the system; and other informationor combinations of information described in detail herein. Any or allelectrodes 541 can comprise a dipole and/or surface charge mappingelectrode, such as an electrode with an impedance or other electricalproperty configured to provide information related to surface charge orother dipole mapping parameter. In some embodiments, the electrodes 541are of sufficiently low impedance, such as in the range less than 10,000ohms, such as to achieve high-fidelity recording of signal frequenciesgreater than or equal to 0.1 Hz. In some embodiments, one or moreelectrodes. 541 include an iridium oxide coating, such as to reduce theimpedance of electrodes 541. Alternatively or additionally, numerousforms of coatings or other treatments can be included with one or moreelectrodes 541, such as a platinum black coating or a carbon nanotubelayer. In addition or as an alternative to recording electric signals,electrodes 541 can be constructed and arranged to deliver electricenergy, such as radiofrequency energy. In some embodiments, diagnosticcatheter 500 can deliver therapy, such as an ablation therapy deliveredto tissue, in addition to its function as a diagnostic catheter, e.g.providing electrical, anatomical and/or device mapping information. Insome embodiments, one or more electrodes 541 each comprise one or morecoils, such as when the one or more coils are configured to create oneor more magnetic fields.

Electrodes 541 can include various materials such as non-polarizingmetals and/or polarizing metals. In some embodiments, one or moreelectrodes 541 comprise at least one non-noble metal such thatelectrodes 541 oxidize when in contact with at least one of blood, bloodplasma or saline solutions. In some embodiments, electrodes 541 includea coating, for example a coating selected from the group consisting of:a metal oxide coating; a conductive polymer coating; and combinations ofthese. In some embodiments, one or more electrodes 541 can include anouter layer and an inner layer, such as when the outer layer comprisesan impedance lowering coating or other layer and the inner layercomprises a layer configured to bond the outer layer to the metallicand/or other remaining portion of the one or more electrodes 541.

Ultrasound transducers 551 can be configured to record distanceinformation such as the distance between any device and/or component ofthe system and tissue such as cardiac wall or other solid tissue.Ultrasound transducers 551 can include a construction comprising: singleor multi-element piezoelectric ceramics; piezoelectric micro-machinedultrasound transducers (pMUT); capacitive micro-machined ultrasoundtransducers (cMUT); piezoelectric polymers; and combinations of these.

In some embodiments, diagnostic catheter 500 can include a multi-layeror laminate construction, for example where shaft 502 includes a tubeinside of another tube; where shaft 502 includes a liner such as a linerconstructed of a lubricous material such as PTFE; where shaft 502includes a braided construction such as a braid positioned between twolayers of shaft 502; and combinations of these. In some embodiments,diagnostic catheter 500 can be steerable, for example via theincorporation of a pull wire and anchor (not shown). Typically,diagnostic catheter shaft 502 outer diameter is less than 15 Fr.

Ablation catheter 520 of FIGS. 5A and 5B includes ablation element 561positioned on shaft 522, for example on a distal portion or the distaltip of shaft 522. Ablation element 561 can include a functional elementselected from the group consisting of: one or more electrodes; a vesselor port configured to deliver cryogenic energy; a laser diode; anoptical fiber configured to deliver ablative light energy; a microwaveenergy delivery element; an ultrasound energy delivery element; a drug,stein cell, or other agent delivery element; an abrasive or othermechanical ablative energy delivery element; and combinations of these.In the case where ablation element 561 includes one or more electrodes,the electrodes can include electrodes constructed and arranged todeliver radiofrequency (RF) energy. In the case of multiple electrodes,the electrodes can be configured for monopolar and/or bipolar RF energydelivery. In some embodiments, ablation element 561 can include an arrayof elements. Ablation catheter 520 can be operably connected to a deviceconfigured to deliver energy to ablation element 561, such as ablationsource 230 of FIG. 3. Typical energy delivered by ablation element 561comprises an energy selected from the group consisting of:electromagnetic energy such as radiofrequency energy; cryogenic energy;laser energy; light energy; microwave energy; ultrasound energy;chemical energy; and combinations of these.

In FIG. 5B, ablation catheter 520 can be steerable, similar todiagnostic catheter 500 and sheath 504, such as via a pull wire andanchor. Here, ablation catheter 520 has been steered in a curvedgeometry 525, as shown, to cause ablation element 561 to exit expandableassembly 530 of diagnostic catheter 500, passing between two middleportions 534 of two splines 531. Ablation catheter 520 can be steeredand advanced by an operator such as a clinician, so as to exit at anyopening of the expandable assembly 530, including the space between twosplines 531 or through opening 535, such as to be further advanced tocontact or move proximate to cardiac tissue, e.g., for ablation.

Various timing sequences can be used for sending and/or recordingsignals to and/or from electrodes 541 and/or USTs 551 on splines 531 ofexpandable assembly 530 in FIGS. 5A and 5B. In the preferred embodiment,a timing sequence is used that provides a pattern of “ringing” the USTsthat alternates between splines. The timing sequence can also includetiming of driving some of the spline electrodes and skin patchelectrodes (optionally included) for localization. In some embodiments,electrodes 541 are continuously recorded. In some embodiments, anelectrode 541 and a UST 551 share a common conductor, and an electrode541 does not record when the UST 551 sharing the common conductor isreceiving a ring signal. The timing sequence of sending and/or recordingsignals can be computer controlled. A full cycle of a timing sequencecan be, for example, 100 ms or less (e.g. a cycle in which a series ofsequential ring signals are sent to each UST 551). In some embodiments,a timing sequence is modified over time, such as to change the time of afull cycle and/or to modify the order in which signals are sent (e.g. toring a UST 551) or recorded (e.g. from an electrode 541).

Referring now to FIG. 5C, a perspective view of an alternative layout ofelectrodes and ultrasound transducers (USTs) positioned on an expandablearray is illustrated, in accordance with aspects of the presentinvention. Probe system 440 includes mapping catheter 500′ and sheath504 through which the distal portion of mapping catheter 500′ has beeninserted. Mapping catheter 500′ includes array 530′ positioned on thedistal end of shaft 502′. Array 530′ comprises multiple splines 531 uponwhich an alternating pattern of a single electrode 541 followed by asingle UST 551 is positioned, as shown. Electrodes 541 and USTs 551 areeach electrically attached to one or more wires which travel proximallywithin shaft 502′, connecting to one or more receivers such as receivers110 and 120 described hereabove in reference to FIG. 1. System 440 caninclude an ablation catheter, such as an ablation catheter similar toablation catheter 520 of FIGS. 5A and 5B. The ablation catheter can beadvanced into the heart alongside shaft 502′ and sheath 504. In someembodiments, shaft 502′ comprises a lumen, such as shaft 502 of FIGS. 5Aand 5B, through which an ablation catheter or other device can beinserted.

FIG. 6 provides an example embodiment of a computer architecture 600that can form part of system 400 configured to determine a databasetable of dipole densities of at least one heart chamber of a patient,which can communicate with the probe system 440 of FIGS. 4, 5A and/or5C, as examples. Architecture 600 can include standard interface modules610 for probe system 440 (and electrodes 442 and/or catheters 500, 500′and 520) and interface modules 620 for interfacing with output devices420, 430. Architecture 600 can further include cardiac informationdisplay controller 650 for receiving, interpreting, generating,processing and/or providing cardiac information. The computer 410includes at least one processor 640 and at least one computer memory 680connected to elements 610, 620, 630, 640 and/or 650 via bus 660 asshown. The architecture 600 further includes an electrical potential tosurface charge density and/or dipole density converter module 630.Module 630 includes executable computer instructions necessary forcarrying out the methods described herein, when executed by processor640, wherein the results of such processing are stored in memory (e.g.,a database, data storage system, or data storage device) 680—as would beunderstood by one skilled in the art having the benefit of thisdisclosure. That is, module 630 is preferably configured to determinedipole and/or surface charge densities from data received, at least inpart, from probe system 440, as described herein or otherwise.

FIG. 7 and FIG. 8 summarize embodiments of methods for determining andstoring surface charge densities and dipole densities in accordance withaspects of the present invention, respectively, which have beendescribed in detail above.

In method 700 of FIG. 7, in Step 702, system 400 is used to measureand/or calculate one or more electric potential(s) V_(e) into one ormore position(s) P within a heart chamber at a given time t. In Step704, V_(e) is transformed into a surface charge density ρ(P′,t). In Step706, the surface charge density ρ(P′,t) is stored in a database table.The method is repeated if there is another P, in Step 708.

In method 800 of FIG. 8, in Step 802, mapping system 400 is used tomeasure and/or calculate one or more electric potential(s) V_(e) in oneor more position(s) P within a heart chamber at a given time t. In Step804, V_(e) is transformed into said dipole density ν(P′,t) by using analgorithm suitable for transforming an electric potential into surfacecharge density. In Step 806, the dipole density ν(P′,t) is stored in adatabase table. The method is repeated if there is another P, in Step808.

In accordance with aspects of the present invention, the architecture600 further includes a cardiac information display (CID) controller 650.In this embodiment, CID controller 650 is configured to generate and/orprovide information sufficient for at least one display device to rendercardiac information, which can include, but is not limited to, dipoledensity and/or surface charge density information. The cardiacinformation could also include cardiac voltage (or potential)information, a graphical model of a heart or portion of a heart (orother organ), images of a heart or portions thereof (or other organ),other local information such as temperature and/or pH information, otherfield information (e.g. other than voltage information), or combinationsthereof. The rendering of the heart and/or portion of the heart (orother organ) could be two-dimensional (2-D), three-dimensional (3-D), orcombinations thereof. Such cardiac information can also include anelectrocardiogram (EKG or ECG), e.g., such as a graph of the heart'selectrical activity versus time. The above types of cardiac informationcould be displayed in various combinations, e.g., to include dipoledensity and/or surface charge density information, and displayed in 2-D,3-D, or combinations thereof.

Such cardiac information could be stored in memory 680 for real-time,near real-time, or subsequent display. The display could be a computermonitor, tablet, smartphone, television, or other type of display deviceor device comprising such a display. The display(s) could be local,remote, or combinations thereof (if more than one display). Thedisplay(s) could be wired, wireless, or combinations thereof (e.g. ifmore than one).

For purposes of describing the differences in the display ofinformation, different types of information can be distinguished. Forexample, dipole and charge density information is different from voltage(or potential) information. For example, dipole and charge densityinformation, e.g., from methods 700 and 800, can be considered to betypes of “source information,” which is data representing, at a locationin 3D space, a physical property or properties discrete to the specificlocation in 3D space, e.g., similar to temperature or pH informationwhich is also source information. In contrast, voltage (or potential)information can be considered to be “field information,” which is datarepresenting, at a location in 3D space, a physical property orproperties of a continuum extending through the 3D space.

FIG. 9 describes an embodiment of a method 900 of displaying dipoleand/or charge density information in at least one electronic or computerdisplay, preferably in conjunction with at least one image of a heart.The method can be implemented by system 400, as an example. In thisembodiment, in Step 902, voltages are measured from multiple cardiaclocations (e.g. within or on the endocardial surface of a heart chamber)using at least one electrode, as field information. In Step 904, fromthe voltages (or field information), a plurality of dipole and/or chargedensities (or source information) are determined by the computerprocessor, e.g., on multiple locations on the surface of the heart, fromthe measured voltages. In Step 906, at least one image of the heart iselectronically rendered on at least one (local and/or remote) displayscreen. In Step 908, a distribution of dipole and/or charge densities iselectronically rendered on the at least one display screen, e.g., inconjunction with the image(s) of the heart. In Step 910, which is anoptional step, a voltage information is electronically rendered on theat least one display screen, e.g., in conjunction with the image(s) ofthe heart. In various embodiments, Step 910 can be a user selectableoptions, wherein, for example, voltage information could be toggled onand off under the user's control.

In some embodiments, Step 902 comprises measuring voltages from an arrayof electrodes, serially or sequentially. In some embodiments, Step 902further comprises moving one or more electrodes from a first location toone or more different locations and measuring voltages from the one ormore electrodes at each location.

In some embodiments, Step 908 comprises rending a series of dipoleand/or charge densities on the display screen, such as a series ofimages representing a complete cardiac cycle (i.e., heartbeat). In theseembodiments, the series of images representing a complete cardiac cyclecan be repeated (i.e. looped). Alternatively or additionally, the seriesof images representing a complete cardiac cycle can be updated (e.g.continuously updated and/or updated at discrete time intervals). In someembodiments, a series of images representing a complete cardiac cyclecan be displayed with a static image of the heart (e.g. a single heartimage rendered on the screen in Step 906, such as an image representingthe end of systole or diastole). Alternatively, a series of imagesrepresenting a complete cardiac cycle can be displayed with acorresponding series (e.g. a temporally corresponding series) of imagesof the heart that show the contraction and expansion of the heart duringa cardiac cycle.

FIG. 10 is an exemplary embodiment of a display 1000 of dipole and/orsurface charge density information that can be generated on one or moredevices, in accordance with aspects of the present invention. In thisexample, dipole density information is shown, but in other embodiments,additionally or alternatively, surface charge density, pH information,temperature information and/or other source or field information couldbe included. Display 1000 could comprise any now known or hereafterdeveloped graphical display, such as a computer monitor, tablet,cellphone, television, display panel, Google glass, and so forth.Alternatively or additionally, information provided on display 1000could be provided on paper such as via a printer, or sent wirelessly toa separate device. Display 1000 can include a patient information box,display area 1002 that provides relevant information about the patient(e.g. patient name, age, hospital patient ID, and the like) from whomthe cardiac information was collected.

Voltage is a “force field” that spreads out from “dipolar” sources ofcharge, (e.g. foci in AF diagnostics), so is field information, as thatterm is used herein. Region of influence typically spans severalcentimeters in a chamber of the heart. Voltage presents a broad, blurredview of the physiologic state, similar to de-focusing a camera lens.Voltage measurements include far-field interference from adjacentlocations such as adjacent chambers. In contrast, dipolar charge sources(e.g. “focal pockets”) are source information, as that term is usedherein, that can be derived from multiple voltage measurements (i.e.,field information). Dipole and surface charge density images represent arefined, high-resolution view of physiologic information that span avery small area (e.g., ˜1 mm or smaller). Far-field interference fromadjacent locations is reduced or eliminated. Therefore, the dipoledensity method is similar to re-focusing a camera lens to significantlyimprove resolution of local physiologic state and activity.

In this embodiment, display 1000 includes a dipole (or surface charge)density display area 1010 in which dipole (or surface charge) densityinformation can be displayed, as a form of source information. In thisexample, the dipole (or surface charge) density information (ν(P′,t))1012 is displayed overlaid on an image of a heart, heart image 1011. Inother embodiments, heart image 1011 is not included. Heart image 1011can be an image or model of the particular heart being analyzed or arepresentative model of a heart, either of which can be stored incomputer memory. The dipole density information 1012 is shown for only aportion of the heart image 1011, which can be a user selectable portion.In some embodiments, the dipole density information 1012 can bedisplayed over substantially all of heart image 1011. In still otherembodiments, the system, e.g., the electrical potential to surfacecharge/dipole density converter module 630, can be configured to renderthe dipole density information 1012 for a portion of the heart to whichthe system attributes abnormal behavior or indications, as diagnosedusing the dipole (or surface charge) density information and/or voltagemeasurement information. The dipole density information 1012 and/or theheart image 1011 can represent a dynamic series of information sets,presented in a dynamic format (e.g. series of sequential frame ofimages). In some embodiments, dipole density information 1012 is updatedthroughout one or more cardiac cycles and presented on a static ordynamic heart image 1011, as described hereabove in reference to themethod of FIG. 9. The dipole density information 1012 or other patientinformation included in display 1000 can be shown via a differentiatingmap, such as a display that differentiates values of information byvarying a parameter selected from the group consisting of: color (e.g. acolor map); contrast; brightness; hue; saturation level; andcombinations thereof.

In some embodiments, display 1000 can include one or more other displayareas provided in conjunction with the dipole (or surface charge)density area 1010. Such other display areas can be secondary displayareas displaying information related to (e.g. related to and/ormathematically derived from) the dipole (or surface charge) densityinformation in area 1010. As an example, a dipole (or surface charge)density time-plot display area 1014 can be provided that can beconfigured to dynamically show a plot of dipole density versus time atone or more heart chamber surface locations (one shown), which couldcorrespond to dynamically changing dipole density information displayedin the dipole (or surface charge) density area 1010 (e.g. shown insynchrony with the information displayed in area 1010). In someembodiments, the surface locations are operator selectable.

The dynamically displayed information (e.g. area 1010, area 1014 and/orother dynamically displayed information displayed on display 1000) canpreferably be played, paused, stopped, rewound, fast forwarded and/orotherwise controlled, using controls 1030. The dipole (or surfacecharge) density area 1010, dipole density time-plot area 1014 and/orother information of displayed on display 1000 can be independentlycontrolled (e.g. via controls 1030) and/or temporally linked (e.g.temporally linked in static or dynamic views), in some embodiments.Another optional secondary display area could be an analysis displayarea 1016. In this embodiment, analysis area 1016 includes diagnosticinformation determined from the dipole density data. More specifically,in this case, the analysis area 1016 indicates an assessment of a heartcondition and/or a cause of a heart condition (e.g., a rotor or otheraberrant electrical activity resulting in an arrhythmia such as atrialfibrillation), at least in part, from the dipole density data. Theindication could include one or more dipole density values andassociated time stamps corresponding to dynamically displayed dipoledensity information in area 1010 that is automatically (e.g. by thesystem) and/or manually (e.g. by an operator of the system) marked forfuture viewing and/or assessment.

In various embodiments, the display 1000 can optionally include a seconddisplay area 1020 (or voltage measurement information area 1020), withinwhich can be electronically rendered the voltage measurement information1022 in conjunction with heart image 1011. Here, in this example, themeasured voltages 1022 are projected or overlaid onto a surface of heartimage 1011. Therefore, in accordance with aspects of the presentinvention, the system and display can overlay the distribution of dipoledensities 1012 on the surface of heart image 1011 and project themeasured voltages 1022 on the surface of the second heart image 1011,e.g., at the same time and in synchrony, as shown. As describedhereabove, the dynamically displayed information in area 1020 canpreferably be played, paused, stopped, rewound, fast forwarded and/orotherwise controlled, using controls 1030 (e.g. independently or insynchrony with area 1010).

In other embodiments, a static, single image of the heart can be shownand the user can have the ability to selectively overlay or projectdipole density information, surface charge density information, and/ormeasured voltage measurement information on the single image. Therefore,display 1000 can include one or more controls (e.g. touch screencontrols) responsive to user interaction to selectively toggle betweenthe rendering of the dipole densities, surface charge densities, and/orvoltage measurements on the image of the heart on the display screen(e.g. sequentially and/or simultaneously such as by using an overlay asdescribed herebelow in reference to FIG. 11).

In some embodiments, display 1000 can include one or more other displayareas (e.g. in conjunction with the voltage measurement information area1020). Such other areas can be secondary areas displaying informationrelated to the voltage measurement information area 1020. As an example,a voltage measurement time-plot 1024 can be provided that can beconfigured to dynamically show a plot of measure voltage versus time atone or more heart chamber surface locations (one shown), which couldcorrespond to dynamically changing voltage measurement informationdisplayed in the voltage measurement information area 1020—at one ormore endocardial surface locations (e.g. synchronized to one or moreoperator selected surface locations) on the same time scale. That is,the time scale is the same as the time scale in the dipole density area1010, and related secondary areas. In various embodiments, the user canselect whether or not areas 1010 and 1020 are synchronized, and whetheror not secondary areas are synchronized with the corresponding primaryarea 1010 and 1020. The dynamically displayed information can preferablybe paused, stopped, rewound, and/or fast forwarded. The voltagemeasurement information area 1020 and voltage measurement informationtime-plot area 1024 and/or other information displayed on display 1000can be independently controlled (e.g. via controls 1030) and/ortemporally linked (e.g. temporally linked in static or dynamic views),in some embodiments.

Another optional secondary area could be an analysis area 1026. In thisembodiment, analysis area 1026 includes diagnostic informationdetermined from the voltage measurement information. More specifically,in this case, the analysis area 1026 indicates a heart condition (e.g.,atrial fibrillation) determined, at least in part, from the voltagemeasurement information. The indication could include a voltagemeasurement information value and time stamp corresponding to thedynamically displayed voltage measurement information in area 1020.

In various embodiments, display 1000 can include one or more graphicalmechanisms or other controls responsive to user interaction to change anorientation in two-dimensional (2D) or three-dimensional (3D) space ofthe image of the heart 1011 with overlaid dipole densities 1012. Forexample, one or more areas can include controls 1032 to zoom in and outor controls 1034 to rotate or turn the heart and overlaid information inan area (e.g., areas 1010 and 1020).

In various embodiments, as noted, the displays in areas 1010 and 1020can be dynamically updated, where the system dynamically updates thedistribution of dipole densities by altering visual characteristicsthereof corresponding to changes in the dipole densities and/or measuredvoltages over time. Altering the visual characteristics can comprisealtering at least one of color, intensity, hue, and shape of at least aportion of the rendered distribution of dipole densities 1012 and/orvoltage measurement information 1022. The electronic rendering of thedistribution of dipole densities 1012 on the display screen can beperformed in real-time in response to voltage measurements obtained inreal-time using the at least one electrode, as described above. Theelectronic rendering of the distribution of dipole densities on thedisplay screen can be performed as post processing and/or analysis basedon voltage measurements stored in at least one computer memory.

The display 1000 can include one or more graphical controls 1040responsive to user interaction to record the user interactions with thedisplay, e.g., on the same temporal time scale as the informationdisplayed in areas 1010 and 1020, and related secondary areas (if any).For example, the system could be configured to receive audio inputs froma user interacting with the display 1000. Inputs that could be recordedand/or saved can include, but are not limited to: text inputs, audioinputs, and graphical inputs (or interactions). In such cases, aPractitioner Notes box 1042 could be included for textual inputs by auser and an audio input control 1044 can be included on enable anddisable audio inputs. Controls 1030 can be used to play, rewind, andfast forward changes in the rendering of the distribution of dipoledensities on the display screen over time, along with any recorded userinteractions.

FIG. 11 is another embodiment of a user interface display 1100 of dipoleand/or surface charge density information that can be generated on oneor more devices, in accordance with aspects of the present invention.The display of FIG. 11 can also include any of the interactive controlsor features of the display of FIG. 10. Display 1100 includes area 1110including one or more anatomical views of physiologic activity on one ormore surfaces of a heart, such as the Right Posterior Oblique (RPO) viewshown on the left and the Left Anterior Oblique (LAO) view shown on theright.

The anatomic images of area 1110 include a representation of sets ofvarying source and/or field data correlated in 3D space with surfaces ofa heart and differentiated in magnitude with a color map, in thepreferred embodiment. Alternatively or additionally, data can bedifferentiated with other graphical properties such as contrast,brightness, hue and/or saturation levels. These value-differentiatingmaps can represent the magnitude of field data (e.g. voltage data)and/or source data (e.g. dipole density or charge density data), e.g.,at the same point in time in each view, simultaneously (e.g. via anoverlay) or sequentially (e.g. by toggling the views). In someembodiments, an image of the heart is also shown, simultaneously orsequentially with the field and/or source data, as described hereabovein reference to FIG. 10. A heart image can comprise a static heart image(e.g. the image of the heart at the end of systole or diastole uponwhich field and/or source information is displayed), or a dynamic heartimage such as a beating heart image. A static or dynamic heart image canbe routinely updated, such as an image that is updated based on signalsreceived from the ultrasound transducers of the present invention.

In some embodiments, field information (e.g. voltage information) andsource information (e.g. dipole density or surface charge densityinformation) is overlaid, such as when voltage data is displayed as a“bottom layer” and dipole density data is partially transparentlydisplayed “on top” of the voltage data. This overlay could be done usingan algorithm that mixes the overlaid colors (a “pigment-based” mixing),or by other methods, such as methods that affect brightness, contrast,or other techniques, known to those skilled in computer colormanipulation and image processing. Different layers can be turned on andoff, or toggled, color schemes modified, views changed, and so on, inresponse to an operator instruction or input or the presence of acondition determined by the computer, e.g., the cardiac informationdisplay controller 650 in FIG. 6. Each view can be controlled or changedindependently or together—as a related pair. Next to each image 1111A,1111B a 3D frame of reference icon 1112A, 1112B is displayed to aid theuser in understanding the orientation of the heart image provided (e.g.anterior, posterior, medial, lateral and combinations of these, allstandard orientations used in clinical imaging).

One or both of the views can display real (or near-real) timeinformation that can dynamically change in response to changes in sourceand/or field information represented in or otherwise used in the views.For example, the information displayed in both views can dynamicallychange in response to measured, sensed, or calculated changes inrepresented source and/or field information, such as voltages, dipoledensity, surface charge density, temperature, pH, and so forth. Suchchanges can be embodied in changes in colors, hues, intensities, dynamicpatterns, and so forth used in the views.

In this embodiment, in conjunction with the anatomical cardiac views,there is displayed an electrocardiogram (EKG or ECG) representingelectrical activity of the heart in EKG area 1120. The EKG area 1120 andanatomical images 1111A, 1111B can dynamically change together, invarious embodiments. EKG area 1120 translates the heart's electricalactivity into line tracings on the display. In various embodiments, theEKG area 1120 can be turned on and off by the user.

In this embodiment, the display includes two tables 1132 and 1134 thatinclude data gathered from the ultrasound transducers, electrodes,and/or other sensors of the present invention. The data (as shown intable 1132) could represent the chamber or system as a whole(Quantitative Data) and can also represent data (as shown in table 1134)specific to a cursor position or area selected by a user (e.g., aphysician), e.g., by drawing a box with a cursor or placing the cursorover the image, as with cursor C (+) in FIG. 11.

In some embodiments, display 1100 further includes area 1121. Area 1121can be configured to provide information provided by one or more of theultrasound transducers, electrodes and/or other sensors of the presentinvention, such as ultrasound transducers 551, electrodes 541 of FIG. 5Cdescribed hereabove. Area 1121 can provide various patient information,such as calculated patient information (hereinafter “calculatedinformation”) as described herein. In some embodiments, area 1121comprises quantitative and/or qualitative patient information related toa physiologic parameter of a patient that comprises calculatedinformation determined by the sensor information (e.g. determined bymathematically processing the sensor information). Calculatedinformation can comprise patient information selected from the groupconsisting of: cardiac chamber volume; cardiac wall thickness; averagecardiac wall thickness; a cardiac chamber dimension; ejection fraction;cardiac output; cardiac flow rate; cardiac contractility; cardiac wallmotion; other cardiac function information; voltage at a cardiac surfacelocation; dipole state at a cardiac surface location; and combinationsthereof. In these embodiments, voltage and/or dipole information can becalculated from signals recorded by one or more electrodes. In theseembodiments, signals from one or more ultrasound transducers can be usedto determine cardiac geometry information. Signals from one or moreultrasound transducers can be analyzed to determine the level or statusone or more of chamber volume; average wall thickness; chamberdimensions; ejection fraction; cardiac output; flow rate; contractility;wall motion; voltage; dipole state; and wall thickness. The informationrecorded by the ultrasound transducers can be used to dynamically definethe geometric shapes of the chambers and walls of the heart, and one ormore algorithms can be included to create quantitative measures of thethese cardiac parameters, avoiding the need for: transesophageol and/orTransthoracic electrocardiography (TTE/TEE) and/or Intracardiac Echo(ICE) to measure wall motion such as abnormal wall motion; FunctionalMRI to measure contractility, cardiac output and/or stroke work;Positron Emission Tomography (PET Scan) and/or Single-Photon EmissionComputed Tomography (SPECT Scan) to measure metabolic performance;Thermodilution and/or Impedance Volumetry catheters to measure cardiacoutput; and combinations of these. In some embodiments, area 1121provides patient information selected from the group consisting of:blood pressure; heart rate; cardiac cycle length; pulse oximetry;respiration rate; and combinations of these. In some embodiments, theinformation provided in area 1121 and/or other areas of display 1100 isupdated relatively continuously over time, e.g. at least every 10seconds. In some embodiments, area 1121 includes an image of the heart,and cardiac information such as those listed above can be displayed inrelation to the heart image (e.g. wall thickness displayed relative tothe associated wall, chamber volume within the associated chamber,etc.). In some embodiments, quantitative information is displayed innumeric form (i.e. graphic elements of display 1100 comprising one ormore numerals). Alternatively or additionally, quantitative informationcan be displayed with one or more graphic elements such as a line chart,bar chart and/or pie chart. In some embodiments, the informationprovided in area 1121 and/or other areas of display 1100 is updated on aperiodic basis, such as once per minute, once per 5 minutes or once per10 minutes. The information provided in area 1121 can be calculatedinformation based on information collected over time, such as patientinformation that is summed, averaged, integrated, differentiated and/orotherwise mathematically processed by one or more algorithms. Thepatient information can comprise source information (e.g. dipole densityof surface charge density information). In some embodiments, one or morealgorithms find an average, a mean, a maximum level, a minimum level ofone or more patient parameters. In some embodiments, one or morealgorithms compare calculated information or other patient informationto a threshold to produce calculated information. For example, if thelevel of a particular parameter exceeds a threshold (e.g. is over amaximum threshold or under a minimum threshold), the system can enter anew state such as an alert state. In some embodiments, after exceeding athreshold, the appearance of already displayed patient information canchange, such as a color change (e.g. a change to red) and/or a fontchange (a change to italics or a change in boldness). Alternatively oradditionally, an alert can be activated (e.g. an audible or tactilealert) to notify an operator of the system (e.g. a clinician) that athreshold has been exceeded.

Referring now to FIG. 12, a flow chart of an embodiment of a method forgenerating a model of a heart and providing a graphical representationof cardiac information on a display screen is illustrated. Method 1200comprises displaying source information (e.g. dipole and/or surfacecharge density information) relative to a heart image on a displayscreen. Other information, such as field information (e.g. voltageinformation or other field information relative to the same or differentcardiac locations) can be displayed, such as in a side-by-sidearrangement, an overlay arrangement and/or an arrangement where the twosets of information are presented sequentially (e.g. toggled back andforth) in the same location (an “alternating arrangement”). In someembodiments, one or more cardiac parameters are quantified or otherwisedetermined utilizing the systems and devices of the present inventiondescribed hereabove. Cardiac parameters determined call include cardiacdimensions (e.g. chamber volume or wall thickness), cardiac functionparameters (e.g. ejection fraction or cardiac output) and/or cardiachealth,

In Step 1210, the distal end of a catheter of the present invention isplaced into one or more body locations, such as one or more cardiacchambers of a patient. The catheter comprises at least one electrode andat least one ultrasound element. The catheter includes one or moreelectrodes positioned on a distal portion of the catheter and configuredto record electrical activity in tissue and/or deliver ablation energy.In Step 1220, anatomical information, such as tissue location, tissuemovement, tissue thickness and/or tissue contour information can bedetermined via the at least one ultrasound element, typically an elementconfigured to transmit and receive ultrasound waves as describedhereabove. Alternatively or additionally, position and/or distanceinformation can be recorded, such as position and/or distanceinformation relative to one or more device components and/or tissuelocations. In Step 1230, source information for one or more tissuelocations can be determined via the at least one electrode, e.g. byrecording voltage reading from multiple locations on and/or within thechamber of the heart and calculated the source information (e.g.calculating dipole density and/or surface charge density information asdescribed hereabove). Steps 1220 and 1230 can be performedsimultaneously or sequentially, in full or partial steps, and in anyorder. Either or both Steps 1220 and 1230 can be performed in two ormore independent time periods.

In Step 1240, at least source information is provided to an operator ofthe system, such as via a display screen or in written form. In someembodiments, information is provided relative to a static image of theheart, such as an image at the end of systole or diastole. Alternativelyor additionally, a dynamic set of heart images can be createdrepresenting a full cardiac cycle, or multiple cardiac cycles createdover the course of a patient treatment procedure such as a cardiacablation procedure performed to treat an arrhythmia such as atrialfibrillation. A dynamic set of source information can be presented on adisplay screen in synchrony with the dynamic set of heart images. Insome embodiments, source information, field information, cardiac imageinformation and/or cardiac parameter information are stored in memory,such as memory 680 of FIG. 6 described hereabove. In these embodiments,playback of stored information can be provided to an operator via thedisplay screen.

In some embodiments, a further analysis of the ultrasound reflectionsrecorded and the electrical charge information is performed. The furtheranalysis can include determining a cardiac parameter selected from thegroup consisting of: cardiac chamber volume; cardiac wall thickness;average cardiac wall thickness; a cardiac chamber dimension; ejectionfraction; cardiac output; cardiac flow rate; cardiac contractility;cardiac wall motion; other cardiac function information; voltage at acardiac surface location; dipole state at a cardiac surface location;and combinations thereof, each of which can be provided to the operatoron a display screen (e.g. information provided in relation to a certaintissue portion of the heart such as wall thickness information providedrelative to the particular cardiac wall). Alternatively or additionally,the further analysis can include producing a diagnosis and/or prognosisof a tissue portion, which can similarly be provided to the operator ona display screen (e.g. information provided in relation to a certaintissue portion of the heart such as cardiac wall motion informationprovided relative to the particular cardiac wall).

For example, electrical information indicative of adequate electricalactivity and anatomical information indicative of adequate tissue motioncan correlate to the presence of healthy tissue. Additionally,electrical information indicative of adequate electrical activity andanatomical information indicative of inadequate tissue motion cancorrelate to presence of at least one of ischemic tissue or hibernatingtissue. Conversely, electrical information indicative of inadequateelectrical activity and anatomical information indicative of inadequatetissue motion can correlate to presence of scar tissue. Additionally,electrical information indicative of inadequate electrical activity andanatomical information indicative of inadequate tissue motion cancorrelate to the presence of a complete ablation, such as an ablationperformed in a cardiac ablation performed to treat a cardiac arrhythmia(e.g. ablation of at least left atrial tissue to treat atrialfibrillation). In some embodiments, the complete ablation comprises atransmural ablation. In this use, the diagnosis and/or prognosisprovided on the display screen can include the confirmation of thecreation of a transmural lesion in the patient's heart tissue, such aswhen both tissue motion and electrical activity have been eliminated ordecreased below a threshold.

More specifically, the following four cases can be determined to exist:

-   -   Case 1: Electrical and anatomical are adequate—Tissue is        healthy,    -   Case 2: Electrical is adequate and anatomical is        inadequate—Tissue is compromised,    -   Case 3: Electrical is inadequate and anatomical is        adequate—Tissue is compromised, and    -   Case 4: Electrical and anatomical are both inadequate—Tissue        necrosis.

The actual threshold for determining adequacy of electrical function ofany one area of the heart is dependent upon many factors, including thedegree of coordination of the activation pattern and the mass of thecells being activated. Additionally, this threshold will be differentfor each chamber of the heart as well as from smaller to largerpatients. For example, a threshold of 0.5 mV can be appropriate, whereinan electrical potential smaller than 0.5 mV can be indicative ofinadequate electrical function and an electrical potential at or largerthan 0.5 mV can be indicative of adequate electrical function. In someembodiments, the thresholds are adjustable via one or more controls ofthe system of the present invention.

In some embodiments, tissue diagnostic algorithms can be configured toallow a clinician to assess the electrical integrity of cardiac cells.For example, the functional status of the cardiac cells can be assessed.In one embodiment, the electrical information comprises dipole densityinformation. Additionally or alternatively, the electrical informationcan comprise at least one of repolarization or speed of repolarizationinformation.

In some embodiments, tissue diagnostic algorithms use recordings fromone or more ultrasound transducers (e.g. one or more ultrasoundtransducers on an array of the present invention) to produce calculatedinformation representing a change in cardiac geometry. The calculatedinformation can represent a measurement of heart contractility, and anundesired level of heart contractility and/or change in heartcontractility can be identified and provided on a display. Thecalculated information can represent a measurement of volume of one ormore cardiac chambers and an undesired level of cardiac chamber volumeand/or change in cardiac chamber volume (e.g. left atrial enlargementthat can occur during an atrial fibrillation procedure) can beidentified and provided on a display. Numerous forms of patientinformation can be assessed, such as via a calculation that creates ameasure of a change in patient information over a time period.

The information collected in Steps 1210 through 1230 and/or informationderived from or otherwise calculated based on the collected informationcan be presented to an operator, such as when area 1121 or another areaof display 1100 of FIG. 11 comprises the collected and/or calculatedinformation.

The method can further comprise the optional Step 1250 comprisingablating or otherwise treating cardiac tissue, such as an ablationperformed based upon source information, tissue diagnostic informationand/or other information provided on a display screen. For example, theanatomical information comprising tissue thickness information and atleast one of the magnitude of ablation energy or the time period inwhich ablation energy is delivered, is adjusted based on the tissuethickness information recorded by one or more ultrasound sensors.Alternatively or additionally, one or more other therapeutic procedurescan be performed. In these therapeutic procedures, various calculatedand/or collected information (e.g. anatomic, physiologic, therapeuticdevice and/or therapeutic procedure information) can be provided to anoperator, such as when area 1121 or another area of display 1100 of FIG.11 comprises the collected and/or calculated information. Suchinformation includes but is not limited to: tissue thicknessinformation; tissue contractility information; tissue densityinformation; tissue temperature information; therapeutic devicecomponent temperature information (e.g. temperature of an electrode);duration of energy delivery information; and combinations of these. Insome embodiments, changes in information are reflected by changes in theway information is displayed, such as density information for a tissuearea changing from a grey or other color to a white or other non-greycolor during ablation of that tissue area.

While the foregoing has described what are considered to be the bestmode and/or other preferred embodiments, it is understood that variousmodifications can be made therein and that the invention or inventionsmay be implemented in various forms and embodiments, and that they maybe applied in numerous applications, only some of which have beendescribed herein. It is intended by the following claims to claim thatwhich is literally described and all equivalents thereto, including allmodifications and variations that fall within the scope of each claim.

1. (canceled) 2-100. (canceled)
 101. A method of generating a graphicalrepresentation of cardiac information on a display screen, comprising:acquiring an anatomical model of the heart including at least onecardiac chamber including multiple cardiac locations; electronicallydetermining multiple sequential data sets of source informationcorresponding to cardiac activity at the multiple cardiac locations,wherein the multiple sequential data sets of source information areelectronically determined at least once per second; electronicallyrendering the anatomical model of the heart including multiple cardiaclocations on the display screen; and electronically rendering calculatedinformation based on the data sets of source information in relation tothe multiple cardiac locations on the display screen.
 102. The method ofclaim 101, or any other claim herein, wherein the anatomical model isupdated at least once every 30 minutes.
 103. The method of claim 101, orany other claim herein, wherein the anatomical model is updated at leastonce every minute.
 104. The method of claim 101, or any other claimherein, wherein the anatomical model is updated at least once everysecond.
 105. The method of claim 101, or any other claim herein, whereinthe anatomical model is updated at least once every 100 milliseconds.106. The method of claim 101, or any other claim herein, wherein theanatomical model is updated at least 30 times per second.
 107. Themethod of claim 101, or any other claim herein, wherein the anatomicalmodel is created using data from a CT and/or an MRI scan.
 108. Themethod of claim 101, or any other claim herein, wherein the anatomicalmodel is created using signals from at least one ultrasound transducer.109. The method of claim 108, wherein the at least one ultrasoundtransducer is positioned within the heart chamber.
 110. The method ofclaim 101, wherein the anatomical model of the heart comprises a staticmodel of the heart.
 111. The method of claim 101, wherein the anatomicalmodel of the heart comprises a dynamic model of the heart beating. 112.The method of claim 101, or any other claim herein, wherein the multiplesequential data sets of source information represent a dynamic series ofinformation sets.
 113. The method of claim 112, wherein the dynamicseries of information sets is updated throughout one or more cardiaccycles.
 114. The method of claim 101, or any other claim herein, whereinthe source information is data representing, at a location in 3D space,a physical property or properties discrete to the specific location in3D space.
 115. The method of claim 101, or any other claim herein,wherein the source information comprises dipole density data determinedfor a point on the surface of the heart.
 116. The method of claim 101,or any other claim herein, wherein the source information comprises:dipole density information; surface charge information; temperatureinformation; pH information; or combinations of two or more thereof.117. The method of claim 101, or any other claim herein, whereinelectronically determining multiple sequential data sets of sourceinformation comprises recording signals from at least one electrode.118. The method of claim 117, wherein the at least one electrodecomprises multiple electrodes.
 119. The method of claim 118, wherein themultiple electrodes are mounted to an expandable array constructed andarranged for placement within a cardiac chamber.
 120. The method ofclaim 101, or any other claim herein, wherein the calculated informationis presented in the form of, or using, a differentiating map.
 121. Themethod of claim 120, wherein the differentiating map comprises a map ofvalue differentiating parameters including: color; contrast; brightness;hue; saturation level; or combinations of two or more thereof.
 122. Themethod of claim 101, or any other claim herein, comprising rendering adata set of field information on the display screen.
 123. The method ofclaim 122, comprising displaying the data set of field information in analternating arrangement with the data set of source information.